| File extension Name |
extension description |
| .3 | IBM Voice Type Language Script Data File |
| .3 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .3 | Salt Lake City Game Music File |
| .3 | Screen Log File |
| .3 | Solaris Device Configuration Assistant Boot Diskette |
| .30 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .300 | NCBridge XP/NC200/NC400/NC900 Series Network Boot Software (Network Computing Devices, Inc.) |
| .301 | Brooktrout Fax-Mail File |
| .301 | Super FAX 2000 or Fax-Mail 96 Fax |
| .303 | Seq-303 Settings |
| .31 | PHASES Phased Structure Factor File |
| .31 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .310 | Tri-Sen TS310 Controller Configuration File (Tri-Sen Systems Inc.) |
| .310SV | Tri-Sen 310sv Controller Configuration File (Tri-Sen Systems Inc.) |
| .32 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .32 | Salt Lake City Game Music File |
| .320 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .320 | Screamtracker 32 File |
| .320 | Tri-Sen 320 Controller Configuration File (Tri-Sen Systems Inc.) |
| .320 | Chromeleon Demo Data File |
| .3200 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .3201 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .323 | H.323 Internet Telephony |
| .32S | Win 32s File |
| .32X | Gens 2.0 File |
| .32X | Kega Fusion ROM Image |
| .32_ | Ntgraph Setup File |
| .330 | NCBridge XP330 Series Network Boot Software (Network Computing Devices, Inc.) |
| .33B | SYNETSIM Source Code |
| .34 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .34 | Salt Lake City Game Music File |
| .340 | Chromeleon Demo Data File |
| .35 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .350 | NCBridge XP Series except XP330 Network Boot Software (Network Computing Devices, Inc.) |
| .36 | Salt Lake City Game Music File |
| .36 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .360 | Backup File |
| .360 | 360desktop 360-Degree Desktop Image (360desktop Pty. Ltd.) |
| .37 | Salt Lake City Game Music File |
| .370 | Printer Driver File |
| .386 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .386 | Windows Enhanced Mode Driver or Swap File (Microsoft Corporation) |
| .38_ | Compressed Tvideo Card NEU File |
| .3A | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .3A3 | STABCAL (stability calculation for aqueous systems) File |
| .3A5 | STABCAL (stability calculation for aqueous systems) File |
| .3B | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .3B1 | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .3B3 | STABCAL (stability calculation for aqueous systems) File |
| .3B5 | STABCAL (stability calculation for aqueous systems) File |
| .3C3 | STABCAL (stability calculation for aqueous systems) File |
| .3C5 | STABCAL (stability calculation for aqueous systems) File |
| .3CN | 3D Movie Maker Scene (Microsoft Corporation) |
| .3D | Atari Stereo CAD-3D Objects Graphics Format (Atari) |
| .3D | Al-Arabi Publisher Document |
| .3D | Advent 3B2 Document |
| .3D | SpinFire Professional Secure 3D Format CAD File (Actify, Inc.) |
| .3D | Cadwork 3D CAD File (cadwork AG) |
| .3D | i3D Browser File (Center for Advanced Studies, Research and Development in Sardinia) |
| .3D | VersaCAD 3D Drawing File |
| .3D | Geocadabra |
| .3D | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .3D2 | Stereo CAD-3D Ver. 2.0 Objects Graphics Format (Atari) |
| .3D2 | 3DPlus2 Graphic (Serif) |
| .3D3 | Grafik Anim File |
| .3D4 | Atari Stereo CAD-3D Objects Graphics Format (Atari) |
| .3DA | Atmosphere World File (AtmosphereWorlds) |
| .3DB | 3D Mark Database (Futuremark Corporation) |
| .3DC | 3DCC Color Scheme |
| .3DC | 3D Canvas 3D Model File (Amabilis Software) |
| .3DD | Grafik Anim File |
| .3DF | Quickdraw 3D File |
| .3DG | 3D Grapher Plot Description File (RomanLab Software) |
| .3DI | Delta Force Object Collection (NovaLogic, Inc.) |
| .3DJ | Pyware 3D Drill File (Pygraphics, Inc.) |
| .3DK | OS/2 Saved SKF Format File (IBM) |
| .3DM | Rhino 3D Model File (Robert McNeel & Associates) |
| .3DM | Quickdraw 3D Metafile (Apple Inc.) |
| .3DM | Cadent 3D Model (Cadent Inc.) |
| .3DM | In3D (Flatland 3DML) Three Dimensional Markup Language |
| .3DM | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .3DMF | QuickDraw 3D Metafile (Apple Inc.) |
| .3DML | Rover 3D Modeling |
| .3DML | In3D (Flatland 3DML) Three Dimensional Markup Language |
| .3DMLW | 3DMLW File (3D Technologies R&D) |
| .3DO | Tank3 Demo File |
| .3DO | Total Annihilation Object File (Cavedog Entertainment) |
| .3DP | 3DMark03 Pro Benchmark File (Futuremark Corporation) |
| .3DP | 3D Plus (Serif) |
| .3DR | 3DMark Benchmark File (Futuremark Corporation) |
| .3DS | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .3DS | 3D Studio 3D Scene (Mesh File) (Autodesk, Inc.) |
| .3DT | Topicscape Database (3D-Scape Limited) |
| .3DT | PhotoModeler File (Eos Systems Inc.) |
| .3DT | 3D Greetings Personal Edition Card (Riverdeep Interactive Learning Limited) |
| .3DV | Grafic 3DV File |
| .3DV | Visual Component File |
| .3DW | Cadai 3D World Description (Cadai) |
| .3DX | Rhino 3D Model File (Robert McNeel & Associates) |
| .3DXML | 3D XML Unzipped (or Zipped) File (Dassault Systemes) |
| .3DZ | Pyware 3D Drill File Archive (Pygraphics, Inc.) |
| .3DZ | Easy 3D Creator Project File |
| .3F | Al-Arabi Publisher Template |
| .3F | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .3F | Advent 3B2 Template |
| .3FX | Corel Chart 3D Effect |
| .3G2 | 3GPP2 Multimedia File |
| .3GP | 3GPP Multimedia File |
| .3GP | Nokia 7650 Video Recorder Video File (Nokia) |
| .3GP2 | 3GPP2 Multimedia File |
| .3GPP | 3GPP Multimedia File |
| .3GR | Device Driver |
| .3GR | Windows SVGA/XVGA Screen Grabber |
| .3H | Advent 3B2 Tag Header |
| .3H | Al-Arabi Publisher Tag Header |
| .3IN | MSN Setup Information |
| .3K | Al-Arabi Publisher Keyboard Definition |
| .3K | Advent 3B2 Keyboard Definition |
| .3M | Al-Arabi Publisher Macro |
| .3M | Advent 3B2 Macro |
| .3MM | 3D Movie Maker Movie (Microsoft Corporation) |
| .3MP | TTCN-3 Toolbox Source Code (Test Description) (Danet Group GmbH) |
| .3NG | AT Time! Internal Log (3ENGIN) |
| .3O | Advent 3B2 Object Graphic |
| .3O3 | STABCAL (stability calculation for aqueous systems) File |
| .3O5 | STABCAL (stability calculation for aqueous systems) File |
| .3P | Advent 3B2 Document Preferences |
| .3PI | ShapeGrabber Scanner File |
| .3PI | 3rd PlanIt |
| .3PS | Man Ps file |
| .3R | Advent 3B2 Raster Image |
| .3R | Al-Arabi Publisher Raster Image |
| .3RF | Advent 3B2 Extensions Script Cross Reference |
| .3S | Advent 3B2 Paragraph Styles |
| .3T | Advent 3B2 Text |
| .3T | Often a manual file |
| .3T | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .3T4 | Binary to ASCII Conversion |
| .3TA | Triple-T Animation |
| .3TF | Crystal Reports (Crystal Decisions) |
| .3TH | 3D Movie Maker Thumbnail Data File (Microsoft Corporation) |
| .3TP | Triple-T Plug-in |
| .3X | Advent 3B2 Entity |
| .3X | Unknown Apple II File (found on Golden Orchard Apple II CD Rom) |
| .3X5 | 3x5 Knowledge Base (Vega-Tek) |
| .3XE | 3DLinX Entity |
| .3~6 | Windows 3.x System File |