Archive and compressed
Main article: List of archive formats

    .cab — A cabinet (.cab) file is a library of compressed files stored as a single file. Cabinet files are used to organize installation files that are copied to the user's system.[1]
    .?Q? — files compressed by the SQ program
    7z — 7-Zip compressed file
    AAC — Advanced Audio Coding
    ace — ACE compressed file
    ALZ — ALZip compressed file
    APK — Applications installable on Android
    AT3 — Sony's UMD Data compression
    .bke — BackupEarth.com Data compression
    ARC
    ARJ — ARJ compressed file
    ASS (also SAS) — a subtitles file created by Aegisub, a video typesetting application (Also a Halo game engine file)
    B — (B file) Similar to .a, but a little less compressed...
    BA — Scifer Archive (.ba), Scifer External Archive Type
    big — Special file compression format used by Electronic Arts for compressing the data for many of EA's games
    BIN — compressed Archive. can be read and used by cd-roms and java, Extractable by 7-zip and WINRAR
    BKF (.bkf) — Microsoft backup created by NTBACKUP.c
    bzip2 (.bz2) —
    bld — Skyscraper Simulator Building
    c4 — JEDMICS image files, a DOD system
    cab — Microsoft Cabinet
    cals — JEDMICS image files, a DOD system
    CLIPFLAIR (.clipflair, .clipflair.zip) — ClipFlair Studio [1] component saved state file (contains component options in XML, extra/attached files and nested components' state in child .clipflair.zip files – activities are also components and can be nested at any depth)
    CPT, SEA — Compact Pro (Macintosh)
    DAA — Closed-format, Windows-only compressed disk image
    deb — Debian install package
    DMG — an Apple compressed/encrypted format
    DDZ — a file which can only be used by the "daydreamer engine" created by "fever-dreamer", a program similar to RAGS, it's mainly used to make somewhat short games.
    DPE — Package of AVE documents made with Aquafadas digital publishing tools.
    .egg — Alzip Egg Edition compressed file
    EGT (.egt) — EGT Universal Document also used to create compressed cabinet files replaces .ecab
    ECAB (.ECAB, .ezip) — EGT Compressed Folder used in advanced systems to compress entire system folders, replaced by EGT Universal Document
    ESS (.ess) — EGT SmartSense File, detects files compressed using the EGT compression system.
    GHO (.gho, .ghs) — Norton Ghost
    Graphics Interchange Format (.gif)
    gzip (.gz) — Compressed file
    IPG (.ipg) — Format in which Apple Inc. packages their iPod games. can be extracted through Winrar
    jar — ZIP file with manifest for use with Java applications.
    LBR (.Lawrence) — Lawrence Compiler Type file
    LBR — Library file
    LQR — LBR Library file compressed by the SQ program.
    LHA (.lzh) — Lempel, Ziv, Huffman
    lzip (.lz) — Compressed file
    lzo
    lzma
    LZX (algorithm)
    MBRWizard archive (.mbw)
    Mc.META files (Mc.META) Used in Minecraft Resource Packs
    MPQ Archives (.mpq) — Used by Blizzard games
    BIN (.bin) — MacBinary
    NTH (.nth) — Nokia Theme Used by Nokia Series 40 Cellphones
    OSZ — Osu! compressed beatmap archive
    PAK — Enhanced type of .ARC archive
    PAR (.par, .par2) — Parchive
    PAF (.paf) — Portable Application File
    PYK (.pyk) — Compressed File
    PK3 (.pk3) — Quake 3 archive (See note on Doom³)
    PK4 (.pk4) — Doom³ archive (Opens similarly to a zip archive.)
    RAR (.rar) — Rar Archive, for multiple file archive (rar to .r01-.r99 to s01 and so on)
    RAG, RAGS — Game file, a game playable in the RAGS game-engine, a free program which both allows people to create games, and play games, games created have the file format "RAG game file"
    RPM — Red Hat package/installer for Fedora, RHEL, and similar systems.
    SEN — Scifer Archive (.sen) — Scifer Internal Archive Type
    SIT (.sitx) — StuffIt (Macintosh)
    SKB — Google Sketchup Backup File
    SZS — Nintendo U8 archive
    TAR — group of files, packaged as one file
    TGZ (.tar.gz) — gzipped tar file
    TB (.tb) — Tabbery Virtual Desktop Tab file
    TIB (.tib) — Acronis True Image backup
    UHA — Ultra High Archive Compression
    UUE (.uue) — unified utility engine — the generic and default format for all things UUe-related.
    VIV — Archive format used to compress data for several video games, including Need For Speed: High Stakes.
    VOL — unknown archive
    VSA — Altiris Virtual Software Archive
    WAX — Wavexpress — A ZIP alternative optimized for packages containing video, allowing multiple packaged files to be all-or-none delivered with near-instantaneous unpacking via NTFS file system manipulation.
    Z — Unix compress file
    zoo — based on LZW
    zip — popular compression format

Physical recordable media archiving

    ISO — The generic file format for most optical media, including CD-ROM, DVD-ROM, Blu-ray Disc, HD DVD and UMD.
    NRG — The proprietary optical media archive format used by Nero applications.
    IMG — For archiving MS-DOS formatted floppy disks, larger optical media and Hard Disk Drives.
    ADF — Amiga Disk Format, for archiving Amiga floppy disks

        ADZ — The GZip-compressed version of ADF.
        DMS — Disk Masher System, a disk-archiving system native to the Amiga.

    DSK — For archiving floppy disks from a number of other platforms, including the ZX Spectrum and Amstrad CPC.
    D64 — An archive of a Commodore 64 floppy disk.
    SDI — System Deployment Image, used for archiving and providing "virtual disk" functionality.
    MDS — DAEMON tools native disc image file format used for making images from optical CD-ROM, DVD-ROM, HD DVD or Blu-ray Disc. It comes together with MDF file and can be mounted with DAEMON Tools.
    MDX — New DAEMON Tools file format that allows to get one MDX disc image file instead of two (MDF and MDS).
    DMG — Macintosh disk image files

(MPEG-1 is found in a .DAT file on a video CD.)

    CDI — DiscJuggler image file
    CUE — CDRWrite CUE image file
    CIF — Easy CD Creator .cif format
    C2D — Roxio / WinOnCD .c2d format
    DAA — PowerISO .daa format
    B6T — BlindWrite 5/6 image file

Computer-aided Design

Computer-aided is a prefix for several categories of tools (e.g., design, manufacture, engineering) which assist professionals in their respective fields (e.g., machining, architecture, schematics).
Computer-aided design (CAD)

Computer-aided design (CAD) software assists engineers, architects and other design professionals in project design.

    3dxml — Dassault Systemes graphic representation
    3MF — Microsoft 3D Manufacturing Format[2]
    ACP — VA Software VA — Virtual Architecture CAD file
    AMF — Additive Manufacturing File Format
    AEC — DataCAD drawing format[3]
    AR — Ashlar-Vellum Argon — 3D Modeling
    ART — ArtCAM model
    ASC — BRL-CAD Geometry File (old ASCII format)
    ASM — Solidedge Assembly, Pro/ENGINEER Assembly
    BIN, BIM — Data Design System DDS-CAD
    BREP — Open CASCADE 3D model (shape)
    CCC — CopyCAD Curves
    CCM — CopyCAD Model
    CCS — CopyCAD Session
    CAD — CadStd
    CATDrawing — CATIA V5 Drawing document
    CATPart — CATIA V5 Part document
    CATProduct — CATIA V5 Assembly document
    CATProcess — CATIA V5 Manufacturing document
    cgr — CATIA V5 graphic representation file
    ckd — KeyCreator CAD Modeling
    ckt — KeyCreator CAD Modeling
    CO — Ashlar-Vellum Cobalt — parametric drafting and 3D modeling
    DRW — Caddie Early version of Caddie drawing — Prior to Caddie changing to DWG
    DFT — Solidedge Draft
    DGN — MicroStation design file
    DGK — Delcam Geometry
    DMT — Delcam Machining Triangles
    DXF — ASCII Drawing Interchange file format — AutoCAD
    DWB — VariCAD drawing file
    DWF — Autodesk's Web Design Format; AutoCAD & Revit can publish to this format; similar in concept to PDF files; Autodesk Design Review is the reader
    DWG — AutoCAD and Open Design Alliance applications, Autodesk Inventor Drawing file
    EASM — SolidWorks eDrawings assembly file
    EDRW — eDrawings drawing file
    EMB — Wilcom ES Designer Embroidery CAD file
    EPRT — eDrawings part file
    EscPcb - "esCAD pcb" EsCAD.pngEsCAD pcb.png data file by Electro-System Japan.pngElectro-System (Japan)
    EscSch - "esCAD sch" EsCAD.pngEsCAD sch.png data file by Electro-System Japan.pngElectro-System (Japan)
    ESW — AGTEK format
    EXCELLON — Excellon file
    EXP — Drawing Express file format
    F3D — Autodesk Fusion 360 project file
    FM — FeatureCAM Part File
    FMZ — FormZ Project file
    G — BRL-CAD Geometry File
    GBR — Gerber file
    GLM — KernelCAD model
    GRB — T-FLEX CAD File
    GTC — GRAITEC Advance file format
    IAM — Autodesk Inventor Assembly file
    ICD — IronCAD 2D CAD file
    IDW — Autodesk Inventor Drawing file
    IFC — buildingSMART for sharing AEC and FM data
    IGES — Initial Graphics Exchange Specification
    Intergraph's Intergraph Standard File Formats
    IPN — Autodesk Inventor Presentation file
    IPT — Autodesk Inventor Part file
    JT — Jupiter Tesselation
    MCD — Monu-CAD (Monument/Headstone Drawing file)
    model — CATIA V4 part document
    OCD — Orienteering Computer Aided Design (OCAD) file
    PAR — Solidedge Part
    PIPE — PIPE-FLO Professional Piping system design file
    PLN — ArchiCad project
    PRT — NX (recently known as Unigraphics), Pro/ENGINEER Part, CADKEY Part
    PSM — Solidedge Sheet
    PSMODEL — PowerSHAPE Model
    PWI — PowerINSPECT File
    PYT — Pythagoras File
    SKP — SketchUp Model
    RLF — ArtCAM Relief
    RVM - AVEVA PDMS 3D Review model
    RVT — Autodesk Revit project files
    RFA — Autodesk Revit family files
    S12 — Spirit file, by Softtech
    SCAD — OpenSCAD 3D part model
    SCDOC — SpaceClaim 3D Part/Assembly
    SLDASM — SolidWorks Assembly drawing
    SLDDRW — SolidWorks 2D drawing
    SLDPRT — SolidWorks 3D part model
    Softimage's dotXSI
    STEP — Standard for the Exchange of Product model data
    STL — Stereo Lithographic data format used by various CAD systems and stereo lithographic printing machines.
    TCT — TurboCAD drawing template
    TCW — TurboCAD for Windows 2D and 3D drawing
    UNV — I-DEAS I-DEAS (Integrated Design and Engineering Analysis Software)
    VC6 — Ashlar-Vellum Graphite — 2D and 3D drafting
    VLM — Ashlar-Vellum Vellum, Vellum 2D, Vellum Draft, Vellum 3D, DrawingBoard
    VS — Ashlar-Vellum Vellum Solids
    WRL — Similar to STL, but includes color. Used by various CAD systems and 3D printing rapid prototyping machines. Also used for VRML models on the web.
    X_B — Parasolids binary format.
    X_T — Parasolids
    XE — Ashlar-Vellum Xenon — for Associative 3D Modeling

Electronic design automation (EDA)

Electronic design automation (EDA), or electronic computer-aided design (ECAD), is specific to the field of electrical engineering.

    BRD — Board file for EAGLE Layout Editor, a commercial PCB design tool
    BSDL — Description language for testing through JTAG
    CDL — Transistor-level netlist format for IC design
    CPF — Power-domain specification in SoC implementation (see also UPF)
    DEF — Gate-level layout
    DSPF — Detailed Standard Parasitic Format, Analog-level parasitics of interconnections in IC design
    EDIF — Vendor neutral gate-level netlist format
    FSDB — Analog waveform format (see also Waveform viewer)
    GDSII — Format for PCB and layout of integrated circuits
    HEX — ASCII-coded binary format for memory dumps
    LEF — Library Exchange Format, physical abstract of cells for IC design
    LIB — Library modeling (function, timing) format
    MS12 — NI Multisim file
    OASIS — Open Artwork System Interchange Standard
    OpenAccess — Design database format with APIs
    SDC — Synopsys Design Constraints, format for synthesis constraints
    SDF — Standard for gate-level timings
    SPEF — Standard format for parasitics of interconnections in IC design
    SPI, CIR — SPICE Netlist, device-level netlist and commands for simulation
    SREC, S19 — S-record, ASCII-coded format for memory dumps
    STIL — Standard Test Interface Language, IEEE1450-1999 standard for Test Patterns for IC
    SV — SystemVerilog source file
    S*P — Touchstone/EEsof Scattering parameter data file — multi-port blackbox performance, measurement or simulated
    UPF — Standard for Power-domain specification in SoC implementation
    V — Verilog source file
    VCD — Standard format for digital simulation waveform
    VHD, VHDL — VHDL source file
    WGL — Waveform Generation Language, format for Test Patterns for IC

Test technology

Files output from Automatic Test Equipment or post-processed from such.

    Standard Test Data Format

Database

    4DB — 4D database Structure file
    4DD — 4D database Data file
    4DIndy — 4D database Structure Index file
    4DIndx — 4D database Data Index file
    4DR — 4D database Data resource file (in old 4D versions)
    ACCDB — Microsoft Database (Microsoft Office Access 2007 and later)
    ACCDE — Compiled Microsoft Database (Microsoft Office Access 2007 and later)
    ADT — Sybase Advantage Database Server (ADS)
    APR — Lotus Approach data entry & reports
    BOX — Lotus Notes Post Office mail routing database
    CHML — Krasbit Technologies Encrypted database file for 1 click integration between contact management software and the chameleon(tm) line of imaging workflow solutions
    DAF — Digital Anchor data file
    DAT — DOS Basic
    DAT — Intersystems Caché database file
    DB — Paradox
    DB — SQLite
    DBF — db/dbase II,III,IV and V, Clipper, Harbour/xHarbour, Fox/FoxPro, Oracle
    EGT — EGT Universal Document, used to compress sql databases to smaller files, may contain original EGT database style.
    ESS — EGT SmartSense is a database of files and its compression style. Specific to EGT SmartSense
    EAP — Enterprise Architect Project
    FDB — Firebird Databases
    FDB — Navision database file
    FP, FP3, FP5, and FP7 — FileMaker Pro
    FRM — MySQL table definition
    GDB — Borland InterBase Databases
    GTABLE — Google Drive Fusion Table
    KEXI — Kexi database file (SQLite-based)
    KEXIC — shortcut to a database connection for a Kexi databases on a server
    KEXIS — shortcut to a Kexi database
    LDB — Temporary database file, only existing when database is open
    MDA — Add-in file for Microsoft Access
    MDB — Microsoft Access database
    ADP — Microsoft Access project (used for accessing databases on a server)
    MDE — Compiled Microsoft Database (Access)
    MDF — Microsoft SQL Server Database
    MYD — MySQL MyISAM table data
    MYI — MySQL MyISAM table index
    NCF — Lotus Notes configuration file
    NSF — Lotus Notes database
    NTF — Lotus Notes database design template
    NV2 — QW Page NewViews object oriented accounting database
    ODB — LibreOffice Base or OpenOffice Base database
    ORA — Oracle tablespace files sometimes get this extension (also used for configuration files)
    PCONTACT — WinIM Contact file
    PDB — Palm OS Database
    PDI — Portable Database Image
    PDX — Corel Paradox database management
    PRC — Palm OS resource database
    SQL — bundled SQL queries
    REC — GNU recutils database
    REL — Sage Retrieve 4GL data file
    RIN — Sage Retrieve 4GL index file
    SDB — StarOffice's StarBase
    SDF — SQL Compact Database file
    sqlite — SQLite
    UDL — Universal Data Link
    waData — Wakanda (software) database Data file
    waIndx — Wakanda (software) database Index file
    waModel — Wakanda (software) database Model file
    waJournal — Wakanda (software) database Journal file
    WDB — Microsoft Works Database
    WMDB — Windows Media Database file — The CurrentDatabase_360.wmdb file can contain file name, file properties, music, video, photo and playlist information.

Desktop publishing

    AI — Adobe Illustrator
    AVE / ZAVE — Aquafadas
    CDR — CorelDRAW
    CHP / pub / STY / CAP / CIF / VGR / FRM — Ventura Publisher — Xerox (DOS / GEM)
    CPT — Corel Photo-Paint
    DTP — Greenstreet Publisher, GST PressWorks
    GDRAW — Google Drive Drawing
    ILDOC — Broadvision Quicksilver document
    INDD — Adobe InDesign
    PSD — Adobe Photoshop
    MCF — FotoInsight Designer
    PDF — Adobe Acrobat or Adobe Reader
    PMD — Adobe PageMaker
    PPP — Serif PagePlus
    PUB — Microsoft Publisher
    QXD — QuarkXPress
    FM — Adobe FrameMaker
    SLA / SCD — Scribus
    WLMP — Windows Live Movie Maker project file

Document

These files store formatted text and plain text.

    0 — Plain Text Document, Normally used for licensing
    1ST — Plain Text Document, Normally preceded by the words "README" (README.1ST)
    600 — Plain Text Document, Used in UNZIP history log
    602 — Text602 document
    ABW — AbiWord Document
    ACL — MS Word AutoCorrect List
    AFP — Advanced Function Presentation — IBc
    AMI — Lostus Ami Pro
    Amigaguide
    ANS — American National Standards Institute (ANSI) text
    ASC — ASCII text
    AWW — Ability Write
    CCF — Color Chat 1.0
    CSV — ASCII text as comma-separated values, used in spreadsheets and database management systems
    CWK — ClarisWorks / AppleWorks document
    DBK — DocBook XML sub-format
    DOC — Microsoft Word document
    DOCM — Microsoft Word macro-enabled document
    DOCX — Office Open XML document
    DOT — Microsoft Word document template
    DOTX — Office Open XML text document template
    EGT — EGT Universal Document
    EPUB — EPUB open standard for e-books
    EZW — Reagency Systems easyOFFER document[4]
    FDX — Final Draft
    FTM — Fielded Text Meta
    FTX — Fielded Text (Declared)
    GDOC — Google Drive Document
    HTML — HyperText Markup Language (.html, .htm)
    HWP — Haansoft (Hancom) Hangul Word Processor document
    HWPML — Haansoft (Hancom) Hangul Word Processor Markup Language document
    LOG — Text log file
    LWP — Lotus Word Pro
    MBP — metadata for Mobipocket documents
    MD — Markdown text document
    ME — Plain text document normally preceded by the word "READ" (READ.ME)
    MCW — Microsoft Word for Macintosh (versions 4.0–5.1)
    Mobi — Mobipocket documents
    NB — Mathematica Notebook
    NBP — Mathematica Player Notebook
    NEIS - 학교생활기록부 작성 프로그램(Student Record Writing Program) Document
    ODM — OpenDocument master document
    ODT — OpenDocument text document
    OTT — OpenDocument text document template

  

    OMM — OmmWriter text document
    PAGES — Apple Pages document
    PAP — Papyrus word processor document
    PDAX — Portable Document Archive (PDA) document index file
    PDF — Portable Document Format
    QUOX — Question Object File Format for Quobject Designer or Quobject Explorer
    Radix-64
    RTF — Rich Text document
    RPT — Crystal Reports
    SDW — StarWriter text document, used in earlier versions of StarOffice
    SE — Shuttle Document
    STW — OpenOffice.org XML (obsolete) text document template
    Sxw — OpenOffice.org XML (obsolete) text document
    TeX — TeX
    INFO — Texinfo
    Troff
    TXT — ASCII nebo Unicode plaintext Text file
    UOF — Uniform Office Format
    UOML — Unique Object Markup Language
    VIA — Revoware VIA Document Project File
    WPD — WordPerfect document
    WPS — Microsoft Works document
    WPT — Microsoft Works document template
    WRD — WordIt! document
    WRF — ThinkFree Write
    WRI — Microsoft Write document
    XHTML (xhtml, XHT..) — eXtensible Hyper-Text Markup Language
    XML — eXtensible Markup Language
    XPS — Open XML Paper Specification

Financial records

    MYO — MYOB Limited (Windows) File
    MYOB — MYOB Limited (Mac) File
    TAX — TurboTax File
    YNAB — You Need a Budget (YNAB) File

Financial data transfer formats

    Interactive Financial Exchange (IFX) — XML-based specification for various forms of financial transactions
    Open Financial Exchange (.ofx) — open standard supported by CheckFree and Microsoft and partially by Intuit; SGML and later XML based
    QFX — proprietary pay-only file format used only by Intuit
    Quicken Interchange Format (.qif) — open standard formerly supported by Intuit

Font file

    ABF — Adobe Binary Screen Font
    AFM — Adobe Font Metrics
    BDF — Bitmap Distribution Format
    BMF — ByteMap Font Format
    FNT — Bitmapped Font — Graphics Environment Manager (GEM)
    FON — Bitmapped Font — Microsoft Windows
    MGF — MicroGrafx Font
    OTF — OpenType Font
    PCF — Portable Compiled Format
    PostScript Font — Type 1, Type 2
        PFA — Printer Font ASCII
        PFB — Printer Font Binary — Adobe
        PFM — Printer Font Metrics — Adobe
        AFM — Adobe Font Metrics
        FOND — Font Description resource — Mac OS
    SFD — FontForge spline font database Font
    SNF — Server Normal Format
    TDF — TheDraw Font
    TFM — TeX font metric
    TTF (.ttf, .ttc) — TrueType Font
    WOFF — Web Open Font Format

Geographic information system

    ASC — ASCII point of interest (POI) text file
    APR — ESRI ArcView 3.3 and earlier project file
    DEM — USGS DEM file format
    E00 — ARC/INFO interchange file format
    GeoJSON —Geographically located data in object notation
    GeoTIFF — Geographically located raster data
    GML — Geography Markup Language file[5]
    GPX — XML-based interchange format
    ITN - TomTom Itinerary format
    MXD — ESRI ArcGIS project file, 8.0 and higher
    NTF — National Transfer Format file
    OV2 — TomTom POI overlay file
    SHP — ESRI shapefile
    TAB — MapInfo Table file format
    World TIFF — Geographically located raster data: text file giving corner coordinate, raster cells per unit, and rotation
    DTED — Digital Terrain Elevation Data
    KML — Keyhole Markup Language, XML-based

Graphical information organizers

    3DT — 3D Topicscape The database in which the meta-data of a 3D Topicscape is held. A 3D Topicscape is a form of 3D concept map (like a 3D mind-map) used to organize ideas, information and computer files.
    ATY — 3D Topicscape file, produced when an association type is exported by 3D Topicscape. Used to permit round-trip (export Topicscape, change files and folders as desired, re-import them to 3D Topicscape).
    CAG — Linear Reference System.
    FES — 3D Topicscape file, produced when a fileless occurrence in 3D Topicscape is exported to Windows. Used to permit round-trip (export Topicscape, change files and folders as desired, re-import them to 3D Topicscape).
    MGMF — MindGenius Mind Mapping Software file format.
    MM — FreeMind mind map file (XML).
    MMP — Mind Manager mind map file.
    TPC — 3D Topicscape file, produced when an inter-Topicscape topic link file is exported to Windows. Used to permit round-trip (export Topicscape, change files and folders as desired, re-import them to 3D Topicscape).

Graphics
Main article: image file formats
Color palettes

    ACT — Adobe Color Table. Contains a raw color palette and consists of 256 24-bit RGB colour values.
    GPL — GIMP palette file
    PAL — Microsoft palette file

Color management

    ICC/ICM — Color profile conforming the specification of the ICC.

Raster graphics

Raster (or Bitmap) files store images as a group of pixels.

    ASE — Adobe Swatch
    ART — America Online proprietary format
    BLP — Blizzard Entertainment proprietary texture format
    BMP — Microsoft Windows Bitmap formatted image
    BTI — Nintendo proprietary texture format
    CD5 — Chasys Draw IES image
    CIT — Intergraph is a monochrome bitmap format
    CPT — Corel PHOTO-PAINT image
    CR2 — Canon camera raw format. Photos will have this format on some Canon cameras if the quality "RAW" is selected in camera settings.
    CUT — Dr. Halo image file
    DDS — DirectX texture file
    DIB — Device-Independent Bitmap graphic
    DjVu — DjVu for scanned documents
    EGT — EGT Universal Document, used in EGT SmartSense to compress PNG files to yet a smaller file
    Exif — Exchangeable image file format (Exif) is a specification for the image file format used by digital cameras
    GIF — CompuServe's Graphics Interchange Format
    GPL — GIMP Palette, using a textual representation of color names and RGB values
    GRF — Zebra Technologies proprietary format
    ICNS — file format use for icons in macOS. Contains bitmap images at multiple resolutions and bitdepths with alpha channel.
    ICO — a file format used for icons in Microsoft Windows. Contains small bitmap images at multiple resolutions and sizes.
    IFF (.iff, .ilbm, .lbm) — ILBM
    JNG — a single-frame MNG using JPEG compression and possibly an alpha channel.
    JPEG, JFIF (.jpg or .jpeg) — Joint Photographic Experts Group — a lossy image format widely used to display photographic images.
    JP2 — JPEG2000
    JPS — JPEG Stereo
    LBM — Deluxe Paint image file
    MAX — ScanSoft PaperPort document
    MIFF — ImageMagick's native file format
    MNG — Multiple Network Graphics, the animated version of PNG
    MSP — a file format used by old versions of Microsoft Paint. Replaced with BMP in Microsoft Windows 3.0
    NITF — A U.S. Government standard commonly used in Intelligence systems
    OTB - Over The Air bitmap, a specification designed by Nokia for black and white images for mobile phones
    PBM — Portable bitmap
    PC1 — Low resolution, compressed Degas picture file
    PC2 — Medium resolution, compressed Degas picture file
    PC3 — High resolution, compressed Degas picture file
    PCF — Pixel Coordination Format
    PCX — a lossless format used by ZSoft's PC Paint, popular at one time on DOS systems.
    PDN — Paint.NET image file
    PGM — Portable graymap
    PI1 — Low resolution, uncompressed Degas picture file
    PI2 — Medium resolution, uncompressed Degas picture file. Also Portrait Innovations encrypted image format.
    PI3 — High resolution, uncompressed Degas picture file
    PICT, PCT — Apple Macintosh PICT image
    PNG — Portable Network Graphic (lossless, recommended for display and edition of graphic images)
    PNM — Portable anymap graphic bitmap image
    PNS — PNG Stereo
    PPM — Portable Pixmap (Pixel Map) image
    PSB — Adobe Photoshop Big image file (for large files)
    PSD, PDD — Adobe Photoshop Drawing
    PSP — Paint Shop Pro image
    PX — Pixel image editor image file
    PXM — Pixelmator image file
    PXR — Pixar Image Computer image file
    QFX — QuickLink Fax image
    RAW — General term for minimally processed image data (acquired by a digital camera)
    RLE — a run-length encoded image
    SCT — Scitex Continuous Tone image file
    SGI, RGB, INT, BW — Silicon Graphics Image
    TGA (.tga, .targa, .icb, .vda, .vst, .pix) — Truevision TGA (Targa) image
    TIFF (.tif or .tiff) — Tagged Image File Format (usually lossless, but many variants exist, including lossy ones)
    TIFF/EP (.tif or .tiff) — ISO 12234-2; tends to be used as a basis for other formats rather than in its own right.
    VTF — Valve Texture Format
    XBM — X Window System Bitmap
    XCF — GIMP image (from Gimp's origin at the eXperimental Computing Facility of the University of California)
    XPM — X Window System Pixmap
    ZIF — Zoomable/Zoomify Image Format (a web-friendly, TIFF-based, zoomable image format)

Vector graphics

Vector graphics use geometric primitives such as points, lines, curves, and polygons to represent images.

    3DV — 3-D wireframe graphics by Oscar Garcia
    AMF — Additive Manufacturing File Format
    AWG — Ability Draw
    AI — Adobe Illustrator Document
    CGM — Computer Graphics Metafile, an ISO Standard
    CDR — CorelDRAW Document
    CMX — CorelDRAW vector image
    DXF — ASCII Drawing Interchange file Format, used in AutoCAD and other CAD-programs
    E2D — 2-dimensional vector graphics used by the editor which is included in JFire
    EGT — EGT Universal Document, EGT Vector Draw images are used to draw vector to a website
    EPS — Encapsulated Postscript
    FS — FlexiPro file
    GBR — Gerber file
    ODG — OpenDocument Drawing
        MOVIE.BYU
        RenderMan
    SVG — Scalable Vector Graphics, employs XML
    Scene description languages (3D vector image formats)
        STL — Stereo Lithographic data format (see STL (file format)) used by various CAD systems and stereo lithographic printing machines. See above.
        VRML Uses .wrl extension — Virtual Reality Modeling Language, for the creation of 3D viewable web images.
        X3D
    SXD — OpenOffice.org XML (obsolete) Drawing
    V2D — voucher design used by the voucher management included in JFire
    VDOC — Vector file format used in AnyCut, CutStorm, DrawCut, DragonCut, FutureDRAW, MasterCut, SignMaster, VinylMaster software by Future Corporation
    VSD - Vector file format used by Microsoft Visio
    VSDX - Vector file format used by MS Visio and opened by VSDX Annotator
    VND — Vision numeric Drawing file used in TypeEdit, Gravostyle.
    WMF — Windows Meta File
    EMF — Enhanced (Windows) MetaFile, an extension to WMF
    ART — Xara — Drawing (superseded by XAR)
    XAR — Xara — Drawing

3D graphics

3D graphics are 3D models that allow building models in real-time or non real-time 3D rendering.

    3DMF — QuickDraw 3D Metafile (.3dmf)
    3DM — OpenNURBS Initiative 3D Model (used by Rhinoceros 3D) (.3dm)
    3MF — Microsoft 3D Manufacturing Format (.3mf)[2]
    3DS — Legacy 3D Studio Model (.3ds)
    ABC — Alembic (computer graphics)
    AC — AC3D Model (.ac)
    AMF — Additive Manufacturing File Format
    AN8 — Anim8or Model (.an8)
    AOI — Art of Illusion Model (.aoi)
    ASM – PTC Creo assembly (.asm)
    B3D — Blitz3D Model (.b3d)
    BLEND — Blender (.blend)
    BLOCK — Blender encrypted blend files (.block)
    BMD3 — Nintendo GameCube first-party proprietary model format (.bmd)
    BDL (BMD4) — Nintendo Wii first-party proprietary model format 2006 - 2010 (.bdl)
    BRRES — Nintendo Wii first-party proprietary model format 2010+ (.brres)
    C4D — Cinema 4D (.c4d)
    Cal3D — Cal3D (.cal3d)
    CCP4 — X-ray crystallography voxels (electron density)
    CFL — Compressed File Library (.cfl)
    COB — Caligari Object (.cob)
    CORE3D — Coreona 3D Coreona 3D Virtual File(.core3d)
    CTM — OpenCTM (.ctm)
    DAE — COLLADA (.dae)
    DFF — RenderWare binary stream, commonly used by Grand Theft Auto III-era games as well as other RenderWare titles
    DPM — deepMesh (.dpm)
    DTS — Torque Game Engine (.dts)
    EGG — Panda3D Engine
    FACT — Electric Image (.fac)
    FBX — Autodesk FBX (.fbx)
    G — BRL-CAD geometry (.g)
    GLM — Ghoul Mesh (.glm)
    IOB - Imagine (3D modeling software) (.iob)
    JAS — Cheetah 3D file (.jas)
    LWO — Lightwave Object (.lwo)
    LWS — Lightwave Scene (.lws)
    LXO — Luxology Modo (software) file (.lxo)
    MA — Autodesk Maya ASCII File (.ma)
    MAX — Autodesk 3D Studio Max file (.max)
    MB — Autodesk Maya Binary File (.mb)
    MD2 — Quake 2 model format (.md2)
    MD3 — Quake 3 model format (.md3)
    MD5 — Doom 3 model format (.md5)
    MDX — Blizzard Entertainment's own model format (.mdx)
    MESH — New York University(.m)
    MESH — Meshwork Model (.mesh)
    MM3D — Misfit Model 3d (.mm3d)
    MPO — Multi-Picture Object — This JPEG standard is used for 3d images, as with the Nintendo 3DS
    MRC — voxels in cryo-electron microscopy
    NIF — Gamebryo NetImmerse File (.nif)
    OBJ — Wavefront .obj file (.obj)
    OFF — OFF Object file format (.off)
    OGEX — Open Game Engine Exchange (OpenGEX) format (.ogex)
    PLY — Polygon File Format / Stanford Triangle Format (.ply)
    PRC — Adobe PRC (embedded in PDF files)
    PRT – PTC Creo part (.prt)
    POV — POV-Ray document (.pov)
    R3D - Realsoft 3D (Real-3D) (.r3d)
    RWX — RenderWare Object (.rwx)
    SIA — Nevercenter Silo Object (.sia)
    SIB — Nevercenter Silo Object (.sib)
    SKP — Google Sketchup file (.skp)
    SLDASM — SolidWorks Assembly Document (.sldasm)
    SLDPRT — SolidWorks Part Document (.sldprt)
    SMD — Valve Studiomdl Data format. (.smd)
    U3D — Universal 3D file format (.u3d)
    VIM — Revizto visual information model format (.vimproj)
    VRML97 — VRML Virtual reality modeling language (.wrl)
    VUE — Vue scene file (.vue)
    VWX — Vectorworks (.vwx)
    WINGS — Wings3D (.wings)
    W3D — Westwood 3D Model (.w3d)
    X — DirectX 3D Model (.x)
    X3D — Extensible 3D (.x3d)
    Z3D — Zmodeler (.z3d)

Links and shortcuts

    Alias (Mac OS)
    JNLP — Java Network Launching Protocol, an XML file used by Java Web Start for starting Java applets over the Internet
    LNK — binary-format file shortcut in Microsoft Windows 95 and later
    APPREF-MS — File shortcut format used by ClickOnce
    URL — INI file pointing to a URL bookmarks/Internet shortcut in Microsoft Windows
    SYM — Symbolic link
    .desktop — Desktop entry on Linux Desktop environments

Mathematical

    Harwell-Boeing file format — a format designed to store sparse matrices
    MML — MathML — Mathematical Markup Language
    ODF — OpenDocument Math Formula
    SXM — OpenOffice.org XML (obsolete) Math Formula

Object code, executable files, shared and dynamically linked libraries

    .8BF files — plugins for some photo editing programs including Adobe Photoshop, Paint Shop Pro, GIMP and Helicon Filter.
    .a — Objective C native static library
    a.out — (no suffix for executable image, .o for object files, .so for shared object files) classic UNIX object format, now often superseded by ELF
    APK — Android Package
    APP — A folder found on macOS systems containing program code and resources, appearing as a single file.
    BAC — an executable image for the RSTS/E system, created using the BASIC-PLUS COMPILE command[6]
    BPL — a Win32 PE file created with Borland Delphi or C++Builder containing a package.
    Bundle — a Macintosh plugin created with Xcode or make which holds executable code, data files, and folders for that code.
    .Class — used in Java
    COFF (no suffix for executable image, .o for object files) — UNIX Common Object File Format, now often superseded by ELF
    COM files — commands used in DOS
    DCU — Delphi compiled unit
    DOL — the file format used by the GameCube and Wii, short for Dolphin, which was the codename of the GameCube.
    .EAR — archives of Java enterprise applications
    ELF — (no suffix for executable image, .o for object files, .so for shared object files) used in many modern Unix and Unix-like systems, including Solaris, other System V Release 4 derivatives, Linux, and BSD)
    expander (see bundle)
    DOS executable (.exe — used in DOS)
    .IPA — apple IOS application executable file. Another form of zip file.
    .JAR — archives of Java class files
    .XPI — PKZIP archive that can be run by Mozilla web browsers to install software)
    Mach-O — (no suffix for executable image, .o for object files, .dylib and .bundle for shared object files) Mach based systems, notably native format of macOS, iOS, watchOS, and tvOS)
    NetWare Loadable Module (.NLM) — the native 32-bit binaries compiled for Novell's NetWare Operating System (versions 3 and newer)
    New Executable (.EXE — used in multitasking ("European") MS-DOS 4.0, 16-bit Microsoft Windows, and OS/2)
    .o — un-linked object files directly from the compiler.
    Portable Executable (.EXE, — used in Microsoft Windows and some other systems)
    Preferred Executable Format — (classic Mac OS for PowerPC applications; compatible with Mac OS X via the Classic emulator)
    .s1es — Executable used for S1ES learning system.
    .so — shared library, typically ELF
    Value Added Process (.VAP) — the native 16-bit binaries compiled for Novell's NetWare Operating System (version 2, NetWare 286, Advanced NetWare, etc.)
    .WAR — archives of Java Web applications
    XBE — Xbox executable
    .XAP — Windows Phone package
    XCOFF — (no suffix for executable image, .o for object files, .a for shared object files) extended COFF, used in AIX
    XEX — Xbox 360 executable

Object extensions

        .VBX — Visual Basic extensions
        .OCX — Object Control extensions

    .TLB — Windows Type Library

Page description language

    DVI — Device independent format
    EGT — Universal Document can be used to store CSS type styles (*.egt)
    PLD
    PCL
    PDF — Portable Document Format
    PostScript (.ps, .ps.gz)
    SNP — Microsoft Access Report Snapshot
    XPS
    XSL-FO (Formatting Objects)
    Configurations, Metadata
        CSS — Cascading Style Sheets
        XSLT, XSL — XML Style Sheet (.xslt, .xsl)
        TPL — Web template (.tpl)

Personal information manager
Main article: Personal information manager

    MSG — Microsoft Outlook task manager
    ORG — Lotus Organizer PIM package
    PST, OST — Microsoft Outlook email communication
    SC2 — Microsoft Schedule+ calendar

Presentation

    GSLIDES — Google Drive Presentation
    KEY, KEYNOTE — Apple Keynote Presentation
    NB — Mathematica Slideshow
    NBP — Mathematica Player slideshow
    ODP — OpenDocument Presentation
    OTP — OpenDocument Presentation template
    PEZ — Prezi Desktop Presentation
    POT — Microsoft PowerPoint template
    PPS — Microsoft PowerPoint Show
    PPT — Microsoft PowerPoint Presentation
    PPTX — Office Open XML Presentation
    PRZ — Lotus Freelance Graphics
    SDD — StarOffice's StarImpress
    SHF — ThinkFree Show
    SHOW — Haansoft(Hancom) Presentation software document
    SHW — Corel Presentations slide show creation
    SLP — Logix-4D Manager Show Control Project
    SSPSS — SongShow Plus Slide Show
    STI — OpenOffice.org XML (obsolete) Presentation template
    SXI — OpenOffice.org XML (obsolete) Presentation
    THMX — Microsoft PowerPoint theme template
    WATCH — Dataton Watchout Presentation

Project management software
Main article: Project management software

    MPP — Microsoft Project

Reference management software
Main article: Reference management software

Formats of files used for bibliographic information (citation) management.

    bib — BibTeX
    enl — EndNote
    ris — Research Information Systems RIS (file format)

Scientific data (data exchange)

    FITS (Flexible Image Transport System) — standard data format for astronomy (.fits)
    Silo — a storage format for visualization developed at Lawrence Livermore National Laboratory
    SPC — spectroscopic data
    EAS3 — binary file format for structured data
    EOSSA - Electro-Optic Space Situational Awareness file format
    OST (Open Spatio-Temporal) — extensible, mainly images with related data, or just pure data; meant as an open alternative for microscope images
    CCP4 — X-ray crystallography voxels (electron density)
    MRC — voxels in cryo-electron microscopy
    HITRAN — spectroscopic data with one optical/infrared transition per line in the ASCII file (.hit)
    .root — hierarchical platform-independent compressed binary format used by ROOT
    Simple Data Format (SDF) — a platform-independent, precision-preserving binary data I/O format capable of handling large, multi-dimensional arrays.

Multi-domain

    NetCDF — Network common data format
    HDR, [HDF], h4 or h5 — Hierarchical Data Format
    SDXF — (Structured Data Exchange Format)
    CDF — Common Data Format
    CGNS — CFD General Notation System
    FMF - Full-Metadata Format

Meteorology

    GRIB — Grid In Binary, WMO format for weather model data
    BUFR — WMO format for weather observation data
    PP — UK Met Office format for weather model data
    NASA-Ames — Simple text format for observation data. First used in aircraft studies of the atmosphere.

Chemistry
Main article: chemical file format

    CML — Chemical Markup Language (CML) (.cml)
    Chemical table file (CTab) (.mol, .sd, .sdf)
    Joint Committee on Atomic and Molecular Physical Data (JCAMP) (.dx, .jdx)
    Simplified molecular input line entry specification (SMILES) (.smi)

Mathematics

    graph6, sparse6 — ASCII encoding of Adjacency matrices (.g6, .s6)

Biology

    Molecular biology and bioinformatics:
        AB1 — In DNA sequencing, chromatogram files used by instruments from Applied Biosystems
        ACE — A sequence assembly format
        ASN.1— Abstract Syntax Notation One, is an International Standards Organization (ISO) data representation format used to achieve interoperability between platforms. NCBI uses ASN.1 for the storage and retrieval of data such as nucleotide and protein sequences, structures, genomes, and PubMed records.
        BAM — Binary compressed SAM format
        BCF — Binary compressed VCF format
        BED — The browser extensible display format is used for describing genes and other features of DNA sequences
        CAF — Common Assembly Format for sequence assembly
        EMBL — The flatfile format used by the EMBL to represent database records for nucleotide and peptide sequences from EMBL databases
        FASTA — The FASTA file format, for sequence data. Sometimes also given as FNA or FAA (Fasta Nucleic Acid or Fasta Amino Acid).
        FASTQ — The FASTQ file format, for sequence data with quality. Sometimes also given as QUAL.
        GCPROJ — The Genome Compiler project. Advanced file format for genetic data to be designed, shared and visualized.
        GenBank — The flatfile format used by the NCBI to represent database records for nucleotide and peptide sequences from the GenBank and RefSeq databases
        GFF — The General feature format is used for describing genes and other features of DNA, RNA and protein sequences
        GTF — The Gene transfer format is used to hold information about gene structure.
        NCBI ASN.1 - Structured ASN.1 format used at National Center for Biotechnology Information for DNA and protein data
        NEXUS — The Nexus file encodes mixed information about genetic sequence data in a block structured format.
        NeXML—XML format for phylogenetic trees
        NWK — The Newick tree format is a way of representing graph-theoretical trees with edge lengths using parentheses and commas and useful to hold phylogenetic trees.
        PDB — structures of biomolecules deposited in Protein Data Bank. Also used for exchanging protein/nucleic acid structures.
        PHD — Phred output, from the basecalling software Phred
        PLN — Protein Line Notation used in proteax software specification
        SAM — Sequence Alignment/Map format, in which the results of the 1000 Genomes Project will be released.
        SBML — The Systems Biology Markup Language is used to store biochemical network computational models
        SCF — Staden chromatogram files used to store data from DNA sequencing
        SFF — Standard Flowgram Format
        SRA - format used by the National Center for Biotechnology Information Short Read Archive to store high-throughput DNA sequence data
        Stockholm — The Stockholm format for representing multiple sequence alignments
        Swiss-Prot — The flatfile format used to represent database records for protein sequences from the Swiss-Prot database
        VCF — Variant Call Format, a standard created by the 1000 Genomes Project that lists and annotates the entire collection of human variants (with the exception of approximately 1.6 million variants).

Biomedical imaging

    Digital Imaging and Communications in Medicine (DICOM) (.dcm)
    Neuroimaging Informatics Technology Initiative (NIfTI)
        .nii — single-file (combined data and meta-data) style
            .nii.gz — gzip-compressed, used transparently by some software, notably the FMRIB Software Library (FSL)
            .gii — single-file (combined data and meta-data) style; NIfTI offspring for brain surface data
        .img,.hdr — dual-file (separate data and meta-data, respectively) style
    AFNI data, meta-data (.BRIK,.HEAD)
    Massachusetts General Hospital imaging format, used by the FreeSurfer brain analysis package
        .MGH — uncompressed
        .MGZ — zip-compressed
    Analyze data, meta-data (.img,.hdr)
    Signed Differential Mapping (SDM) brain maps and/or distributions (.sdm)
    Medical Imaging NetCDF (MINC) format, previously based on NetCDF; since version 2.0, based on HDF5 (.mnc)

Biomedical signals (time series)

    ACQ — AcqKnowledge File Format for Windows/PC from Biopac Systems Inc., Goleta, CA, USA.
    ADICHT — LabChart File Format from ADInstruments Pty Ltd, Bella Vista NSW, Australia.
    BCI2000 — The BCI2000 project, Albany, NY, USA.
    BDF — BioSemi data format from BioSemi B.V. Amsterdam, Netherlands.
    BKR — The EEG data format developed at the University of Technology Graz, Austria.
    CFWB — Chart Data File Format from ADInstruments Pty Ltd, Bella Vista NSW, Australia.
    DICOM — Waveform An extension of Dicom for storing waveform data
    ecgML — A markup language for electrocardiogram data acquisition and analysis.
    EDF/EDF+ — European Data Format.
    FEF — File Exchange Format for Vital signs, CEN TS 14271.
    GDF v1.x — The General Data Format for biomedical signals — Version 1.x.
    GDF v2.x — The General Data Format for biomedical signals — Version 2.x.
    HL7aECG — Health Level 7 v3 annotated ECG.
    MFER — Medical waveform Format Encoding Rules
    OpenXDF — Open Exchange Data Format from Neurotronics, Inc. Gainesville, FL, USA.
    SCP-ECG — Standard Communication Protocol for Computer assisted electrocardiography EN1064:2007,
    SIGIF — A digital SIGnal Interchange Format with application in neurophysiology.
    WFDB — Format of Physiobank
    XDF — eXtensible Data Format

Other Biomedical Formats

    Health Level 7 (HL7) — a framework for exchange, integration, sharing, and retrieval of health information electronically
    xDT — a family of data exchange formats for medical records

Biometric Formats

    CBF — Common Biometric Format, based upon CBEFF 2.0 (Common Biometric Exchange Formats Framework).
    EBF — Extended Biometric Format. Based on CBF but with S/MIME encryption support and semantic extensions
    CBFX — XML Common Biometric Format, based upon XCBF 1.1 (OASIS XML Common Biometric Format)
    EBFX — XML Extended Biometric Format, based on CBFX but with W3C XML Encryption support and semantic extensions

Script

    AHK — AutoHotkey script file
    APPLESCRIPT- applescript — see SCPT
    AS — Adobe Flash ActionScript File
    AU3 — AutoIt version 3
    BAT — Batch file
    BAS — QBasic & QuickBASIC
    CLJS - ClojureScript
    CMD — Batch file
    Coffee — CoffeeScript
    duino — Arduino IDE sketch (program)
    EGG — Chicken
    EGT — EGT Asterisk Application Source File, EGT Universal Document
    ERB — Embedded Ruby, Ruby on Rails Script File
    HTA — HTML Application
    IBI — Icarus script
    ICI — ICI
    IJS — J script
    .ipynb - IPython Notebook
    ITCL — Itcl
    JS — JavaScript and JScript
    JSFL — Adobe JavaScript language
    LUA — Lua
    M — Mathematica package file
    MRC — mIRC Script
    NCF — NetWare Command File (scripting for Novell's NetWare OS)
    NUC — compiled script
    NUD — C++ External module written in C++
    NUT — Squirrel
    PHP — PHP
    PHP? — PHP (? = version number)
    PL — Perl
    PM — Perl module
    PS1 — Windows PowerShell shell script
    PS1XML — Windows PowerShell format and type definitions
    PSC1 — Windows PowerShell console file
    PSD1 — Windows PowerShell data file
    PSM1 — Windows PowerShell module file
    PY — Python
    PYC — Python byte code files
    PYO — Python
    R — R scripts
    RB — Ruby
    RDP — RDP connection
    SCPT — Applescript
    SCPTD — See SCPT.
    SDL — State Description Language
    SH — Shell script
    SYJS — SyMAT JavaScript
    SYPY — SyMAT Python
    TCL — Tcl
    VBS — Visual Basic Script
    XPL — XProc script/pipeline
    ebuild — Gentoo linux's portage package.

Security

Authentication and general encryption formats are listed here.

    OpenPGP Message Format — used by Pretty Good Privacy, GNU Privacy Guard, and other OpenPGP software; can contain keys, signed data, or encrypted data; can be binary or text ("ASCII armored")

Certificates and keys

    GXK — Galaxkey, an encryption platform for authorized, private and confidential email communication
    OpenSSH private key (.ssh) — Secure Shell private key; format generated by ssh-keygen or converted from PPK with PuTTYgen[7][8][9]
    OpenSSH public key (.pub) — Secure Shell public key; format generated by ssh-keygen or PuTTYgen[7][8][9]
    PuTTY private key (.ppk) — Secure Shell private key, in the file format generated by PuTTYgen instead of the format used by OpenSSH[7][8][9]

X.509

    Distinguished Encoding Rules (.cer, .crt, .der) — stores certificates
    PKCS#7 SignedData (.p7b, .p7c) — commonly appears without main data, just certificates or certificate revokation lists (CRLs)
    PKCS#12 (.p12, .pfx) — can store public certificates and private keys
    PEM — Privacy-enhanced Electronic Mail: full format not widely used, but often used to store Distinguished Encoding Rules in Base64 format
    PFX — Microsoft predecessor of PKCS#12

Encrypted files

This section shows file formats for encrypted general data, rather than a specific program's data.

    AXX — encrypted file, created with Axcrypt
    EEA — An encrypted CAB, ostensibly for protecting email attachments
    TC — virtual encrypted disk container, created by TrueCrypt

Password files

Password files (sometimes called keychain files) contain lists of other passwords, usually encrypted.

    BPW — encrypted password file created by Bitser password manager
    KeePass 1 database (.kdb)
    KeePass 2 database (.kdbx)

Signal data (non-audio)

    ACQ — AcqKnowledge File Format for Windows/PC from Biopac
    ADICHT — LabChart File Format from ADInstruments
    BKR — The EEG data format developed at the University of Technology Graz
    BDF — BioSemi data format — similar to EDF but 24bit
    CFG — Configuration file for Comtrade data
    CFWB — Chart Data File Format from ADInstruments
    DAT — Raw data file for Comtrade data
    EDF — European data format
    FEF — File Exchange Format for Vital signs
    GDF — General data formats for biomedical signals
    GMS — Gesture And Motion Signal format
    IROCK — intelliRock Sensor Data File Format
    MFER — Medical waveform Format Encoding Rules
    SAC — Seismic Analysis Code, earthquake seismology data format[10]
    SCP-ECG — Standard Communication Protocol for Computer assisted electrocardiography
    SEED — Standard for the Exchange of Earthquake Data, seismological data and sensor metadata[11] (.seed, .mseed)
    SEG Y — Reflection seismology data format (.segy)
    SIGIF — SIGnal Interchange Format
    WIN, WIN32 — NIED/ERI seismic data format (.cnt)[12]

Sound and music
Lossless audio

    Uncompressed
        8SVX — Commodore-Amiga 8-bit sound (usually in an IFF container)
        16SVX — Commodore-Amiga 16-bit sound (usually in an IFF container)
        AIFF (.aif, .aifc, .aiff) — Audio Interchange File Format
        AU
        BWF — Broadcast Wave Format (BWF), an extension of WAVE
        CDDA
        RAW — raw samples without any header or sync
        WAV — Microsoft Wave
    Compressed
        RA — Real Audio format
        FLAC — (free lossless codec of the Ogg project)
        LA — Lossless Audio (.la)
        PAC — LPAC (.pac)
        M4A — Apple Lossless (M4A)
        APE — Monkey's Audio (APE)
        OptimFROG (.ofr, .ofs, .off)
        RKA — RKAU (.rka)
        SHN — Shorten (SHN)
        TAK — Tom's Lossless Audio Kompressor (TAK)[13]
        TTA — free lossless audio codec (True Audio)
        WV — WavPack (.wv)
        WMA — Windows Media Audio 9 Lossless (WMA)
        BRSTM — Binary Revolution Stream (.brstm)[14]
        DTS/DTSHD/DTSMA — DTS (sound system)
        AST — Nintendo Audio Stream (.ast)[15]
        AW — Nintendo Audio Sample used in first-party games (.aw)

Lossy audio

    AMR — for GSM and UMTS based mobile phones
    MP1 — MPEG Layer 1
    MP2 — MPEG Layer 2
    MP3 — MPEG Layer 3
    SPX — Speex (Ogg project, specialized for voice, low bitrates)
    GSM — GSM Full Rate, originally developed for use in mobile phones
    WMA — Windows Media Audio (.WMA)
    AAC (.m4a, .mp4, .m4p, .aac) — Advanced Audio Coding (usually in an MPEG-4 container)
    MPC — Musepack
    VQF — Yamaha TwinVQ
    RealAudio (RA, RM)
    OTS — Audio File (similar to MP3, with more data stored in the file and slightly better compression; designed for use with OtsLabs' OtsAV)
    SWA — Macromedia Shockwave Audio (Same compression as MP3 with additional header information specific to Macromedia Director
    VOX — Dialogic ADPCM Low Sample Rate Digitized Voice (VOX)
    VOC — Creative Labs Soundblaster Creative Voice 8-bit & 16-bit (VOC) Also output format of RCA Audio Recorders
    DWD — DiamondWare Digitized (DWD)
    SMP — Turtlebeach SampleVision (SMP)

Music notation

    LY — LilyPond sheet music file
    MUS, MUSX — Finale sheet music file
    MusicXML (.mxl, .xml) — standard sheet music exchange format
    MSCX, MSCZ – MuseScore sheet music file
    NIFF — Notation Interchange File Format
    PTB — Power Tab Editor tab
    SIB — Sibelius sheet music file

Other music

    ASF — Advanced Systems Format
    AUP — Audacity project file
    CUST — DeliPlayer custom sound file format
    DVR-MS — Windows XP Media Center Edition's Windows Media Center recorded television format
    GYM — Genesis YM2612 log
    JAM — Jam music format
    MID, MIDI — standard MIDI file; most often just notes and controls but occasionally also sample dumps
    MT2 — MadTracker 2 module. It could be resumed as being XM and IT combined with more features like track effects and automation.
    MNG — BGM for the Creatures game series, starting from Creatures 2
    MOD — Soundtracker and Protracker sample and melody modules
        S3M — Scream Tracker 3 module
        XM — Fast Tracker module
        IT — Impulse Tracker module
    NSF — NES Sound Format, bytecode program to play NES music
    PSF — Portable Sound Format, PlayStation variant (originally PlayStation Sound Format)
        minipsf, psflib — Multipart PSF
        2sf, dsf, gsf, psf2, qsf, ssf, usf — PSF for other platforms
    RMJ — RealJukebox Media used for RealPlayer.
    SID — Sound Interface Device — Commodore 64 instructions to play SID music and sound effects
    SPC — Super NES sound file format
    TXM — Track ax media
    VGM — stands for "Video Game Music", log for several different chips
    WTV — Windows Vista's and up Windows Media Center recorded television format
    YM — Atari ST/Amstrad CPC YM2149 sound chip format

Playlists

    AIMPPL - AIMP Playlist format
    ASX — Advanced Stream Redirector (.asx)
    M3U
    PLS
    RAM — Real Audio Metafile For RealAudio files only.
    TXT/No extension — Mplayer playlist
    XPL — HDi playlist
    XSPF — the XML Shareable Playlist Format
    ZPL — Xbox Music (Formerly Zune) Playlist format from Microsoft

Audio editing, music production

    ALS — Ableton Live set
    ALC — Ableton Live clip
    AUP — Audacity project file
    BAND — GarageBand project file
    CEL — Adobe Audition loop file (Cool Edit Loop)
    CPR — Steinberg Cubase project file
    CWP — Cakewalk Sonar project file
    DRM — Steinberg Cubase drum file
    DMKIT — Image-Line's Drumaxx drum kit file
    LOGIC — Logic Pro X project file
    MMR — MAGIX Music Maker project file
    MX6HS — Mixcraft 6 Home Studio project file
    NPR — Steinberg Nuendo project file
    OMFI — Open Media Framework Interchange OMFI succeeds OMF (Open Media Framework)
    SES — Adobe Audition multitrack session file
    SFL — Sound Forge sound file
    SNG — MIDI sequence file (MidiSoft, Korg, etc.) or n-Track Studio project file
    STF — StudioFactory project file. It contains all necessary patches, samples, tracks and settings to play the file.
    SND — Akai MPC sound file
    SYN — SynFactory project file. It contains all necessary patches, samples, tracks and settings to play the file.
    FLP — Image Line Fruity Loops Project file
    FTM — Famitracker Project file
    VCLS — VocaListener project file
    VSQ — Vocaloid 2 Editor sequence excluding wave-file
    VSQX — Vocaloid 3 Editor sequence excluding wave-file

Source code for computer programs

(see also: Script)

    ADA, ADB, 2.ADA — Ada (body) source
    ADS, 1.ADA — Ada (specification) source
    ASM, S — Assembly language source
    BAS — BASIC, FreeBASIC, Visual Basic, BASIC-PLUS source,[6] PICAXE basic
    BB — Blitz3D
    BMX — BlitzMax
    C — C source
    CLJ — Clojure source code
    CLS — Visual Basic class
    COB, CBL — COBOL source
    CPP, CC, CXX, C, CBP — C++ source
    CS — C# source
    CSPROJ — C# project (Visual Studio .NET)
    D — D source
    DBA — DarkBASIC source
    DBPro123 — DarkBASIC Professional project
    E — Eiffel source
    EFS — EGT Forever Source File
    EGT — EGT Asterisk Source File, could be J, C#, VB.net, EF 2.0 (EGT Forever)
    EL — Emacs Lisp source
    FOR, FTN, F, F77, F90 — Fortran source
    FRM — Visual Basic form
    FRX — Visual Basic form stash file (binary form file)
    FTH — Forth source
    GED — Game Maker Extension Editable file as of version 7.0
    GM6 — Game Maker Editable file as of version 6.x
    GMD — Game Maker Editable file up to version 5.x
    GMK — Game Maker Editable file as of version 7.0
    GML — Game Maker Language script file
    GO — Go source
    H — C/C++ header file
    HPP, HXX — C++ header file
    HS — Haskell source
    I — SWIG interface file
    INC — Turbo Pascal included source
    JAVA — Java source
    L — lex source
    LGT — Logtalk source
    LISP — Common Lisp source
    M — Objective-C source
    M — MATLAB
    M — Mathematica
    M4 — m4 source
    ML — Standard ML / OCaml source
    MSQR — M² source file, created by Mattia Marziali
    N — Nemerle source
    NB — Nuclear Basic source
    P — Parser source
    PAS, PP, P — Pascal source (DPR for projects)
    PHP, PHP3, PHP4, PHP5, PHPS, Phtml — PHP source
    pisrc − PiNET source code mains. Used with Python 3.0, Snap!, and UnrealEngine 4 files source- used by PiIT, Dangerous_Pi, and Silicon Alchemy
    PIV — Pivot stickfigure animator
    PL, PM — Perl
    PLI, PL1 — PL/I
    PRG — Ashton-Tate; dbII, dbIII and dbIV, db, db7, clipper, Microsoft Fox and FoxPro, harbour, xharbour, and Xbase
    PRO — IDL
    POL — Apcera Policy Language doclet
    PY — Python source
    R — R source
    RED — Red source
    REDS — Red/System source
    RB — Ruby source
    RESX — Resource file for .NET applications
    RC, RC2 — Resource script files to generate resources for .NET applications
    RKT, RKTL — Racket source
    SCALA — Scala source
    SCI, SCE — Scilab
    SCM — Scheme source
    SD7 — Seed7 source
    SKB, SKC — Sage Retrieve 4GL Common Area (Main and Amended backup)
    SKD — Sage Retrieve 4GL Database
    SKF, SKG — Sage Retrieve 4GL File Layouts (Main and Amended backup)
    SKI — Sage Retrieve 4GL Instructions
    SKK — Sage Retrieve 4GL Report Generator
    SKM — Sage Retrieve 4GL Menu
    SKO — Sage Retrieve 4GL Program
    SKP, SKQ — Sage Retrieve 4GL Print Layouts (Main and Amended backup)
    SKS, SKT — Sage Retrieve 4GL Screen Layouts (Main and Amended backup)
    SKZ — Sage Retrieve 4GL Security File
    SLN — Visual Studio solution
    SPIN — Spin source (for Parallax Propeller microcontrollers)
    STK — Stickfigure file for Pivot stickfigure animator
    SWG — SWIG source code
    TCL — TCL source code
    VAP — Visual Studio Analyzer project
    VB — Visual Basic.NET source
    VBG — Visual Studio compatible project group
    VBP, VIP — Visual Basic project
    VBPROJ — Visual Basic .NET project
    VCPROJ — Visual C++ project
    VDPROJ — Visual Studio deployment project
    XPL — XProc script/pipeline
    XQ — XQuery file
    XSL — XSLT stylesheet
    Y — yacc source

Spreadsheet

    123 — Lotus 1-2-3
    AB2 — Abykus worksheet
    AB3 — Abykus workbook
    AWS — Ability Spreadsheet
    BCSV — Nintendo proprietary table format
    CLF — ThinkFree Calc
    CELL — Haansoft(Hancom) SpreadSheet software document
    CSV — Comma-Separated Values
    GSHEET — Google Drive Spreadsheet
    numbers — An Apple Numbers Spreadsheet file
    gnumeric — Gnumeric spreadsheet, a gziped XML file
    ODS — OpenDocument spreadsheet
    OTS — OpenDocument spreadsheet template
    QPW — Quattro Pro spreadsheet
    SDC — StarOffice StarCalc Spreadsheet
    SLK — SYLK (SYmbolic LinK)
    STC — OpenOffice.org XML (obsolete) Spreadsheet template
    SXC — OpenOffice.org XML (obsolete) Spreadsheet
    TAB — tab delimited columns; also TSV (Tab-Separated Values)
    TXT — text file
    VC — Visicalc
    WK1 — Lotus 1-2-3 up to version 2.01
    WK3 — Lotus 1-2-3 version 3.0
    WK4 — Lotus 1-2-3 version 4.0
    WKS — Lotus 1-2-3
    WKS — Microsoft Works
    WQ1 — Quattro Pro DOS version
    XLK — Microsoft Excel worksheet backup
    XLS — Microsoft Excel worksheet sheet (97–2003)
    XLSB — Microsoft Excel binary workbook
    XLSM — Microsoft Excel Macro-enabled workbook
    XLSX — Office Open XML worksheet sheet
    XLR — Microsoft Works version 6.0
    XLT — Microsoft Excel worksheet template
    XLTM — Microsoft Excel Macro-enabled worksheet template
    XLW — Microsoft Excel worksheet workspace (version 4.0)

Tabulated data

    TSV — Tab-separated values
    CSV — Comma-separated values
    db — databank format; accessible by many econometric applications
    dif — accessible by many spreadsheet applications

Video
Main article: video file format

    AAF — mostly intended to hold edit decisions and rendering information, but can also contain compressed media essence
    3GP — the most common video format for cell phones
    GIF — Animated GIF (simple animation; until recently often avoided because of patent problems)
    ASF — container (enables any form of compression to be used; MPEG-4 is common; video in ASF-containers is also called Windows Media Video (WMV))
    AVCHD — Advanced Video Codec High Definition
    AVI — container (a shell, which enables any form of compression to be used)
    BIK (.bik) — Bink Video file. A video compression system developed by RAD Game Tools
    CAM — aMSN webcam log file
    COLLAB — Blackboard Collaborate session recording
    DAT — video standard data file (automatically created when we attempted to burn as video file on the CD)
    DSH
    DVR-MS — Windows XP Media Center Edition's Windows Media Center recorded television format
    FLV — Flash video (encoded to run in a flash animation)
    M1V MPEG-1 — Video
    M2V MPEG-2 — Video
    FLA — Macromedia Flash (for producing)
    FLR — (text file which contains scripts extracted from SWF by a free ActionScript decompiler named FLARE)
    SOL — Adobe Flash shared object ("Flash cookie")
    M4V — (file format for videos for iPods and PlayStation Portables developed by Apple)
    Matroska (*.mkv) — Matroska is a container format, which enables any video format such as MPEG-4 ASP or AVC to be used along with other content such as subtitles and detailed meta information
    WRAP — MediaForge (*.wrap)
    MNG — mainly simple animation containing PNG and JPEG objects, often somewhat more complex than animated GIF
    QuickTime (.mov) — container which enables any form of compression to be used; Sorenson codec is the most common; QTCH is the filetype for cached video and audio streams
    MPEG (.mpeg, .mpg, .mpe)
    THP — Nintendo proprietary movie/video format

        MPEG-4 Part 14, shortened "MP4" — multimedia container (most often used for Sony's PlayStation Portable and Apple's iPod)

    MXF — Material Exchange Format (standardized wrapper format for audio/visual material developed by SMPTE)
    ROQ — used by Quake 3
    NSV — Nullsoft Streaming Video (media container designed for streaming video content over the Internet)
    Ogg — container, multimedia
    RM — RealMedia
    SVI — Samsung video format for portable players
    SMI — SAMI Caption file (HTML like subtitle for movie files)
    SMK (.smk) — Smacker video file. A video compression system developed by RAD Game Tools
    SWF — Macromedia Flash (for viewing)
    WMV — Windows Media Video (See ASF)
    WTV — Windows Vista's and up Windows Media Center recorded television format
    YUV - Raw video format - Resolution (horizontal x vertical)and Sample structure 4:2:2 or 4:2:0 need to be known explicitly

Video editing, production

    FCP — Final Cut Pro project file
    MSWMM — Windows Movie Maker project file
    PPJ & PRPROJ— Adobe Premiere Pro video editing file
    IMOVIEPROJ — iMovie project file
    VEG & VEG-BAK — Sony Vegas project file
    SUF — Sony camera configuration file (setup.suf) produced by XDCAM-EX camcorders
    WLMP — Windows Live Movie Maker project file
    KDENLIVE — Kdenlive project file
    VPJ — VideoPad project file
    MOTN — Apple Motion project file
    IMOVIEMOBILE — Apple IMovie for IOS users

Video game data

List of common file formats of data for video games on systems that support filesystems, most commonly PC games.

    TrackMania United/Nations Forever Engine — File formats used by games based on the TrackMania engine.
        XeX
        CHALLENGE.GBX — (Edited) Challenge files.
        CONSTRUCTIONCAMPAIGN.GBX — Construction campaignes files.
        CONTROLEFFECTMASTER.GBX/CONTROLSTYLE.GBX — Menu parts.
        FIDCACHE.GBX — Saved game.
        GBX — Other TrackMania items.
        REPLAY.GBX — Replays of races.
    Doom engine — File formats used by games based on the Doom engine.
        DEH — DeHackEd files to mutate the game executable (not officially part of the DOOM engine)
        DSG — Saved game
        LMP — A lump is an entry in a DOOM wad.
        LMP — Saved demo recording
        MUS — Music file (usually contained within a WAD file)
        WAD — Data storage (contains music, maps, and textures)
    Quake engine — File formats used by games based on the Quake engine.
        BSP — (For Binary space partitioning) compiled map format
        MAP — Raw map format used by editors like GtkRadiant or QuArK
        MDL/MD2/MD3/MD5 — Model for an item used in the game
        PAK/PK2 — Data storage
        PK3/PK4 — used by the Quake II, Quake III Arena and Quake 4 game engines, respectively, to store game data, textures etc. They are actually .zip files.
        .dat — not specific file type, often generic extension for "data" files for a variety of applications
            sometimes used for general data contained within the .PK3/PK4 files
            .fontdat — a .dat file used for formatting game fonts
        .roq — Video format
        .sav — Savegame format
    Unreal Engine — File formats used by games based on the Unreal engine.
        U — Unreal script format
        UAX — Animations format for Unreal Engine 2
        UMX — Map format for Unreal Tournament
        UMX — Music format for Unreal Engine 1
        UNR — Map format for Unreal
        UPK — Package format for cooked content in Unreal Engine 3
        USX — Sound format for Unreal Engine 1 and Unreal Engine 2
        UT2 — Map format for Unreal Tournament 2003 and Unreal Tournament 2004
        UT3 — Map format for Unreal Tournament 3
        UTX — Texture format for Unreal Engine 1 and Unreal Engine 2
        UXX — Cache format. These are files that client downloaded from server (which can be converted to regular formats)
    Duke Nukem 3D Engine — File formats used by games based on the Duke Nukem 3D engine.
        DMO — Save game
        GRP — Data storage
        MAP — Map (usually constructed with BUILD.EXE)
    Diablo Engine — File formats used by Diablo by Blizzard Entertainment.
        SV — Save Game
        ITM — Item File
    Real Virtuality Engine — File formats used by Bohemia Interactive. Operation:Flashpoint, ARMA 2, VBS2
        SQF — Format used for general editing
        SQM — Format used for mission files
        PBO — Binarized file used for compiled models
        LIP — Format that is created from WAV files to create in-game accurate lip-synch for character animations.
    Other Formats
        B — used for Grand Theft Auto saved game files
        BOL — used for levels on Poing!PC
        DBPF — The Sims 2, DBPF, Package
        DIVA — Project DIVA timings, element coördinates, MP3 references, notes, animation poses and scores.
        HE0, HE2, HE4 HE games File
        GCF — format used by the Steam content management system for file archives
        IMG — format used by Renderware-based Grand Theft Auto games for data storage
        LOVE - Format used by the LOVE2D Engine[16]
        MAP — format used by Halo: Combat Evolved for archive compression, Doom³, and various other games
        NBT — format used by Minecraft for storing program variables along with their (Java) type identifiers
        OEC — format used by OE-Cake for scene data storage
        P3D — format for panda3d by Disney
        POD — format used by Terminal Reality
        REP — used by Blizzard Entertainment for scenario replays in StarCraft.
        Simcity 4, DBPF (.dat, .SC4Lot, .SC4Model) — All game plugins use this format, commonly with different file extensions
        SMZIP — ZIP-based package for Stepmania songs, themes and announcer packs.
        VVVVVV — format used by VVVVVV[17]
        CPS— format used by The Powder Toy, Powder Toy stamp

Video game storage media

List of the most common filename extensions used when a game's ROM image or storage medium is copied from an original ROM device to an external memory such as hard disk for back up purposes or for making the game playable with an emulator. In the case of cartridge-based software, if the platform specific extension is not used then filename extensions ".rom" or ".bin" are usually used to clarify that the file contains a copy of a content of a ROM. ROM, disk or tape images usually do not consist of a single file or ROM, rather an entire file or ROM structure contained within a single file on the backup medium.[18]

    JAG,J64 — Atari Jaguar (.jag, .j64)
    BIN — Wii (.bin, iso)
    GCM — GameCube (.gcm, iso)
    NDS — Nintendo DS (.nds)
    3DS — Nintendo 3DS (.3ds)

        CIA — Installation File (.cia)

    GB — Game Boy (.gb) (this applies to the original Game Boy and the Game Boy Color)

        GBC — Game Boy Color (.gbc)
        GBA — Game Boy Advance (.gba)

    GBA — Game Boy Advance (.gba)

        SAV — Game Boy Advance Saved Data Files (.sav)
        SGM — Visual Boy Advance Save States (.sgm)

    N64, V64, Z64, U64, USA, JAP, PAL, EUR, BIN — Nintendo 64 (.n64, .v64, .z64, .u64, .usa, .jap, .pal, .eur, .bin)

        PJ — Project 64 Save States (.pj)

    NES — Nintendo Entertainment System (.nes)

        FDS — Famicom Disk System (.fds)
        JST — Jnes Save States (.jst)
        FC? — FCEUX Save States (.fc#, where # is any character, usually a number)

    GG — Game Gear (.gg)
    SMS — Master System (.sms)
    SMD,BIN — Mega Drive/Genesis (.smd or .bin)
    SMC,078,SFC — Super NES (.smc, .078, or .sfc) (.078 is for split ROMs, which are rare)

        FIG — Super Famicom (Japanese releases are rarely .fig, above extensions are more common)
        SRM — Super NES Saved Data Files (.srm)
        ZST — ZSNES Save States (.zst, .zs1-.zs9, .z10-.z99)
        FRZ — Snes9X Save States (.frz, .000-.008)

    PCE — TurboGrafx-16/PC Engine (.pce)
    NPC — Neo Geo Pocket (.npc)
    TZX — ZX Spectrum (.tzx) (for exact copies of ZX Spectrum games)

        TAP (for tape images without copy protection)
        Z80,SNA — (for snapshots of the emulator RAM)
        DSK — (for disk images)

    TAP — Commodore 64 (.tap) (for tape images including copy protection)

        T64 — (for tape images without copy protection, considerably smaller than .tap files)
        D64 — (for disk images)
        CRT — (for cartridge images)

    ADF — Amiga (.adf) (for 880K diskette images)

        ADZ — GZip-compressed version of the above.
        DMS — Disk Masher System, previously used as a disk-archiving system native to the Amiga, also supported by emulators.

Virtual machines
Microsoft Virtual PC, Virtual Server

    VFD — Virtual Floppy Disk (.vfd)
    VHD — Virtual Hard Disk (.vhd)
    VUD — Virtual Undo Disk (.vud)
    VMC — Virtual Machine Configuration (.vmc)
    VSV — Virtual Machine Saved State (.vsv)

EMC VMware ESX, GSX, Workstation, Player

    LOG — Virtual Machine Logfile (.log)
    VMDK, DSK — Virtual Machine Disk (.vmdk, .dsk)
    NVRAM — Virtual Machine BIOS (.nvram)
    VMEM — Virtual Machine paging file (.vmem)
    VMSD — Virtual Machine snapshot metadata (.vmsd)
    VMSN — Virtual Machine snapshot (.vmsn)
    VMSS,STD — Virtual Machine suspended state (.vmss, .std)
    VMTM — Virtual Machine team data (.vmtm)
    VMX,CFG — Virtual Machine configuration (.vmx, .cfg)
    VMXF — Virtual Machine team configuration (.vmxf)

Virtualbox

    VDI — VirtualBox Virtual Disk Image (.vdi)

Parallels Workstation
Main article: Parallels Workstation

    HDD — Virtual Machine hard disk (.hdd)
    PVS — Virtual Machine preferences/configuration (.pvs)
    SAV — Virtual Machine saved state (.sav)

QEMU

    COW — Copy-on-write
    QCOW — QEMU copy-on-write Qcow
    QCOW2 — QEMU copy-on-write — version 2 Qcow
    QED — QEMU enhanced disk format

Webpage

    Static
        dtd, Document Type Definition (standard), MUST be public and free
        HTML — (.html, .htm) — HyperText Markup Language
        XHTML — (.xhtml, .xht) — eXtensible HyperText Markup Language
        MHTML — (.mht, .mhtml) — Archived HTML, store all data on one web page (text, images, etc.) in one big file
        MAF — (.maff) — web archive based on ZIP
    Dynamically generated
        ASP — (.asp) — Microsoft Active Server Page
        ASPX — (.aspx) — Microsoft Active Server Page. NET
        ADP — AOLserver Dynamic Page
        BML — (.bml) — Better Markup Language (templating)
        CFM — (.cfm) — ColdFusion
        CGI — (.cgi)
        iHTML — (.ihtml) — Inline HTML
        JSP — (.jsp) JavaServer Pages
        Lasso — (.las, .lasso, .lassoapp) — A file created or served with the Lasso Programming Language
        PL — Perl (.pl)
        PHP — (.php, .php?, .phtml) — ? is version number (previously abbreviated Personal Home Page, later changed to PHP: Hypertext Preprocessor)
        RNA — (.rna) — Real Native Application File
        R — (.r) — Real Native Application File (short alternative)
        RNX — (.rnx) — Real Native Application File (using experimental version 6 of RNA/Karbon Language)
        SSI — (.shtml) — HTML with Server Side Includes (Apache)
        SSI — (.stm) — HTML with Server Side Includes (Apache)

Markup languages other web standards-based file formats

    Atom — (.atom, .xml) — Another syndication file format
    EML — (.eml) — File format used by several desktop email clients
    JSON-LD — (.jsonld) — A JSON-based Serialization for Linked Data
    Metalink — (.metalink, .met) — A file format for listing metadata about downloads, such as mirrors, checksums, and other information.
    RSS — (.rss, .xml) — Syndication file format
    Markdown — (.markdown, .md) — A light-weight, plain-text, easy to read and write markup language.
    Shuttle — (.se) — lightweight markup language

Other

    AXD — cookie extensions found in temporary internet folder
    BDF — Binary Data Format — raw data from recovered blocks of unallocated space on a hard drive
    CBP — CD Box Labeler Pro, CentraBuilder, Code::Blocks Project File, Conlab Project[19]
    CEX — SolidWorks Enterprise PDM Vault File
    COL — Nintendo GameCube proprietary collision file (.col)
    CREDX — CredX Dat File
    DDB — Generating code for Vocaloid singers voice (see .DDI)
    DDI — Vocaloid phoneme library (Japanese, English, Korean, Spanish, Chinese, Catalan)
    DUPX — DuupeCheck database management tool project file
    GA3 — Graphical Analysis 3
    GEDCOM (.ged) — (GEnealogical Data COMmunication) file format for exchanging genealogical data between different genealogy software
    HLP — Windows help file
    IGC — flight tracks downloaded from GPS devices in the FAI's prescribed format
    INF — similar file format to INI file; used to install device drivers under Windows, inter alia.
    JAM — JAM Message Base Format for BBSes
    KMC — tests made with KatzReview's MegaCrammer
    KCL — Nintendo GameCube/Wii proprietary collision file (.kcl)
    LSM — LSMaker script file (program using layered .jpg to create special effects; specifically designed to render lightsabers from the Star Wars universe) (.lsm)
    OER — AU OER TOOL, Open Educational Resource editor
    PA — Used for assigning sound effects to materials in KCL files (.pa)
    PIF — Used for running MS-DOS programs under Windows
    POR — So called "portable" SPSS files, readable by PSPP
    PXZ — Compressed file to exchange media elements with PSALMO
    RISE — File containing RISE generated information model evolution
    TOPC — TopicCrunch SEO Project file holding keywords, domain and search engine settings (ASCII);
    TOS — Character file from The Only Sheet
    XLF — Extensible LADAR Format
    XMC — Assisted contact lists file format, based on xml and used in kindergartens and schools
    ZED — My Heritage Family Tree
    Zone file — a text file containing a DNS zone

Cursors

    ANI — Animated Cursor
    CUR — Cursor file
    Smes — Hawk's Dock configuration file

Generalized files
General data formats

These file formats are fairly well defined by long-term use or a general standard, but the content of each file is often highly specific to particular software or has been extended by further standards for specific uses.
Text-based

    CSV — comma-separated values
    HTML — hyper text markup language
    CSS — cascading style sheets
    INI — a configuration text file whose format is substantially similar between applications
    JSON — an openly used data file format used by many languages, not just JavaScript
    TSV — tab-separated values
    XML — an open data file format
    YAML — an open data file format
    ReStructuredText- an open textual format for technical documents used primarily in the Python programming language
    Markdown- an open lightweight markup language for creating simple but rich text, often used to format README files
    AsciiDoc - an open human-readable markup document format semantically equivalent to DocBook

Generic file extensions

These are filename extensions and broad types reused frequently with differing formats or no specific format by different programs.
Binary files

    Bak file (.bak, .bk) — various backup formats: some just copies of data files, some in application-specific data backup formats, some formats for general file backup programs
    BIN — binary data, often memory dumps of executable code or data to be re-used by the same software that originated it
    DAT — data file, usually binary data proprietary to the program that created it
    DSK — file representations of various disk storage images
    RAW — raw (unprocessed) data

Text files

    configuration file (.cnf, .conf, .cfg) — substantially software-specific
    logfiles (.log) — usually text, but sometimes binary
    plain text (.asc or .txt) — human-readable plain text, usually no more specific

Partial files
Differences and patches

    diff — text file differences created by the program diff and applied as updates by patch

Incomplete transfers

     !UT — partially completed downloads in uTorrent
    PART (.part) — partially completed downloads in Mozilla Firefox
    CRDOWNLOAD (.crdownload) - partially completed downloads in Google Chrome
    OPDOWNLOAD (.opdownload) - partially completed downloads in Opera