| grf | GEM Graph Document |
| grf | Grapher Document |
| grf | Micrografx Graph Plus Drawing |
| grg | GreatFamily Graphic Gallery |
| grs | Esko Packedge GRS Document |
| gsa | Microsoft Office Groove 2007 Archived Workspace |
| gsb | Grisbi Document |
| gsd | Graphtec ROBO Master Vector Graphics |
| gsd | Profibus Generic Station Description |
| gsh | GenStat Spreadsheet |
| gsheet | Google Drive Sheet |
| gslide | Google Slides Document |
| gslides | Google Drive Presentation |
| gsp | Silhouette Studio SD Card Document |
| gsp | Sketchpad Document |
| gst | Graphtec ROBO Master Template |
| gstencil | OmniGraffle Stencil |
| gstudio | Graphtec Studio Document |
| gsw | GraphShow Worksheet |
| gta | Microsoft Office Groove 2007 Archive |
| gtc | Graitec Exchange Format Document |
| gtemplate | OmniGraffle Template |
| gtp | Guitar Pro Tabulature |
| gtt | Guntrams Tabletweaving Thingy Pattern |
| gtx | GX Text Document |
| guide | Amigaguide Hypertext Document |
| gul | JungUm Global Document |
| gv | Graphviz DOT File |
| gvdesign | Gravit Designer Document |
| gwb | GenStat Book |
| gwb | Interwrite Presentation Document |
| gwk | GraphiCode PCB Job |
| gx | Geometry Expressions Document |
| gxd | General CADD Pro Drawing |
| han | Headline Studio Animation |
| hbk | Mathcad Handbook Document |
| hbl | Braille Sense Format File |
| hcdt | Thinkfree Office NEO Cell Template |
| hcdx | Hallmark Card Studio Document |
| hcr | Broderbund PrintMaster Half-fold Card Data |
| hdd | HotDisc Designer Document |
| hdml | Handheld Device Markup Language |
| hdrp | HDRtist Document |
| hdw | Harvard Graphics Drawing |
| heb | DEcomp 3D Scene |
| hed | HighEdit Document |
| hef | Efficient PIM v1 Data |
| hf | RayShade HeightField Format |
| hfd | HotDocs Form Document |
| hft | HaftiX Cross-stitch Design |
| hft | HotDocs Envoy-based Form Template |
| hgo | Home Group Overhead Document |
| hht | Help and Support Center HHT |
| hhtml | Realmedia Adstream HTML |
| hhtx | IdeaMax Document |
| highland | Highland Document |
| hip | Houdini Scene |
| hipnc | Houdini Apprentice |
| hjt | Treepad v6 Database |
| hlp | Windows Help File |
| hlz | MultiEdit Packed Help File |
| hmk | Hallmark Card Studio Document |
| hmw | Homeword for DeskMate Document |
| hnc | NoteCenter Notes Document |
| hne | NoteCenter Encrypted Notes Document |
| hou | ARCHLine v4 Drawing |
| hp8 | HP NewWave Write Text |
| hpd | HotDocs PDF Document |
| hpl | HotDocs Answer Source |
| hpm | HP NewWave EMM Text |
| hpo | HippoDraw Canvas Document |
| hpp | Haluha Pearls Design |
| hpt | HotDocs PDF-based Form Template |
| hpux | HP Unix related Readme Text |
| hrx | Herolab E.A.S.Y Document |
| hsdt | Hancom Office Hanshow Template |
| hsdt | Thinkfree Office NEO Show Template |
| hsf | HOOPS Stream File |
| htc | HTML Component |
| htd | HyperTRANSCRIBE Document |
| htm | Hypertext Markup Language Document |
| htmhjt | Treepad v6 Text Database |
| htx | Extended HTML Template |
| htxt | WebKNotes HTXT Document |
| hu | Hungarian Language Info File |
| hus | Husqvarna Viking Embroidery Design |
| huv | Husqvarna Viking Designer Graphic Data |
| hvs | Cubicon Cubicreator G-Code |
| hwdt | Thinkfree Office NEO Word Template |
| hwp | Hangul Word Processor Document |
| hwpx | Hangul Word Processor 2010 Document |
| hwt | Hangul Word Processor Template |
| hxl | Microsoft Help 2 Registered Namespace List |
| hxn | Hexagon 3D Model |
| hxs | MS Help 2 Compiled Help |
| hyp | Adobe Acrobat Spelling Dictionary |
| hyp | Atari ST Guide Data |
| hype | Hype Document |
| hypetemplate | Hype Document Template |
| hyy | HiTi Photo Desiree v2 Template |
| hz | Chinese Hanzi Text File |
| i4d | Inform4 Document |
| iam | Autodesk Inventor Assembly Model |
| iba | Lectra Clothing Design Pieces Document |
| ibcd | InstantBingoCard Document |
| ic3d | IronCAD Compose 3D Scene |
| icd | IronCAD 3D Drawing Document |
| icdl | Internet Content Description Language |
| icdx | FilePic Document |
| icm | ICEM Surf Model |
| icma | Adobe InCopy CS4 Assignment File |
| icml | Adobe InCopy Markup Language Document |
| icmt | Adobe InCopy CS4 Template |
| icp | Intercept Pantheon Schematic Data |
| ics | iCalendar Data |
| ics | IronCAD Scene |
| icw | InterCAD Document |
| ide | Autodesk Inventor iFeature File |
| idea | Adobe Ideas Document |
| idi | I-DEAS Document |
| ido | Infini-D 3D Object |
| idraw | iDraw Document |
| idrw | Claris Impact Drawing Document |
| ids | Infini-D Scene |
| idv | Autodesk Inventor Design View |
| idw | Autodesk Inventor Drawing |
| ifcxml | Industry Foundation Classes XML |
| ifd | InForm Document |
| ife | InfoFind Encrypted Document |
| ig2 | Catia IGES Document |
| ig4 | Image Systems Group 4 Fax Document |
| igds | Bentley MicroStation Design |
| igf | Intercept Geometry File |
| igj | iGrafx Published Web Content |
| igp | Igor Engraver Published Music Notation |
| igr | SmartSketch Drawing |
| igs | IGES Drawing |
| igt | iGrafx Document Template |
| igx | iGrafx Document |
| ihf | IGOR Pro Help File |
| ihf | Inspiration Handheld Document |
| iif | Intuit QuickBooks Interchange File |
| ijpds | Scitex IJPDS File |
| iks | Microsoft InkSeine Document |
| ila | DATEV Document |
| ildoc | Interleaf Document |
| ilg | InstallShield Log |
| imm | iMindmap 4 Document |
| imp | Impatica Classic Document |
| imp | Lotus Improv Spreadsheet |
| imp | TEX-DESIGN Clothing Design Document |
| imr | Impromptu Report File |
| imtx | iMindMap Template File |
| imx | iMindMap 5 Exported Document |
| inca | Adobe InCopy CS3 Assignment File |
| incd | Adobe InCopy 2.0 Document |
| inct | Adobe InCopy CS3 Template |
| incx | Adobe InCopy Interchange Document |
| indb | Adobe InDesign Book |
| indl | Adobe InDesign Library |
| indn | Adobe InDesign for Mac Document |
| indt | Adobe InDesign Template |
| inf | Inspiration Mind Mapping Data |
| info | GNU Info Document |
| infopathxml | Microsoft InfoPath XML Form |
| inkml | Ink Markup Language File |
| inld | ImageNow Document Link |
| inm | Caere FaxMaster Fax |
| inp | InPage Urdu Document |
| ins | Inspiration Document |
| inscribe | InScribe 2004 Document |
| insx | InScribe XML Document |
| intaglio | Intaglio Drawing |
| iob | TurboSilver 3D Object |
| ior | Maxwell Render Index of Refraction Data |
| ipd | Impact CAD Drawing |
| ipdoc | InPrint 3 Document |
| ipf | Intercept Part File |
| ipn | Autodesk Inventor Presentation |
| ipr | SMART Ideas Document |
| ipt | Autodesk Inventor Part |
| ipv | Ibis Paint X Drawing |
| ipv | iCAD Professional Document |
| ipw | UniPlot Graph |
| iqy | Microsoft Excel Web Query |
| irf | Autodesk Impression Drawing |
| irr | Irrlicht 3D Scene |
| irrmesh | Irrlicht 3D Static Mesh |
| is2 | IRT Cronista Infrared Image |
| isdoc | Information System Document |
| isf | Inspiration Concept Map Document |
| isf | Intercept Symbol File |
| isf | ModelPress Compressed CAD Model |
| iso | Arbortext IsoDraw Illustration |
| isoz | Compressed Arbortext IsoDraw Illustration |
| ispx | iStudio Publisher Document |
| ist | Inspiration Template Document |
| itms | iTunes Music Store Link |
| itmz | iThoughtsHD Document |
| iv | OpenInventor 3D Data |
| ive | OpenSceneGraph Native Binary File |
| ivi | MSDN InfoViewer Topic Data |
| ivnu | Inetba Web Page |
| ivt | MSDN InfoViewer Title Data |
| iwa | IBM Writing Assistant Document |
| iwr | iwrite.4.life Document |
| iwtpl | Incomedia Website X5 Template |
| ix | Adobe FrameMaker Index Data |
| ixp | ISIPublisher Publication Export |
| ixt | ISIPublisher Publication Template |
| ixv | IXOS/Open Text Document |
| j2 | Gargoyle Story Document |
| j3s | Java3D Scene |
| jaj | Jarnal Document |
| jas | Cheetah3D Native Model |
| jaw | Ichitaro 5.0 Document |
| jbg | Jarnal Background Image |
| jbs | DesignArt Vector Graphics Data |
| jbw | Ichitaro 6.0 Document |
| jce | JWPce Document |
| jcz | Microsoft Liquid Motion Animation |
| jdf | Alpha Journal Pro Document |
| jdf | My Personal Diary Document |
| jdm | Jade Diagram Document |
| jfc | JWPce Flash Card File |
| jfm | JetForm Filler Form |
| jfw | Ichitaro 7.0 Document |
| jgc | JGCGen Script |
| jgx | JGraphpad v5 Document |
| jhd | Jagannatha Hora Document |
| jis | Japanese Industry Standard Text |
| jlqm | LG QuickMemo Notes |
| jm | jMusic Music Score |
| jmf | Jarnal Metafile |
| jnb | SigmaPlot Workbook |
| jnt | Microsoft Windows Journal Document |
| joc | Context4 Document |
| jot | Autodesk Fabrication Job Template |
| jot3 | Jot+ Notes Note Data |
| jp1 | Japanese Romaji Text |
| jpynb | Jupyter Notebook Document |
| jrp | Electric Quilt Document |
| jrwr | Novel Writer Document |
| jsd | HP JetSuite Document |
| jsw | Ichitaro 4.0 Document |
| jt | JT Open 3D Model |
| jtd | Ichitaro Document |
| jtdc | Ichitaro Compressed Document |
| jtp | Microsoft Windows Journal Template |
| jtt | Ichitaro Template |