| FM | Adobe FrameMaker Document |
| FM | FileMaker Pro Spreadsheet |
| FM1 | Lotus 1-2-3 2.x Spreadsheet |
| FM3 | Lotus 1-2-3 3.x Spreadsheet |
| FM3 | Harvard Graphics Driver |
| FM3 | FileMaker 3 Database Document |
| FMB | Oracle Binary Form Source Code |
| FMB | WordPerfect File Manager Button Bar |
| FMD | Open Access File |
| FMK | Fortran MAK |
| FML | GetRight File Mirror List |
| FML | Oracle Mirror List |
| FMO | dBase Ordered Format |
| FMP | FileMaker Pro Document |
| FMS | Fractal Music Binary |
| FMT | Microsoft Schedule+ Print File |
| FMT | Lotus 1-2-3 format |
| FMT | Style Sheet (various) |
| FMT | FoxPro Format |
| FMT | Borland Sprint Style Sheet |
| FMT | Oracle Text Form Format |
| FMT | Format File (various) |
| FMV | FrameMaker Picture, Bitmap Picture or Vector Drawing |
| FMX | Oracle Executable Form |
| FN3 | Harvard Graphics Font |
| FNC | Frogans Network Certificate |
| FND | Microsoft Explorer Saved Search File |
| FNG | Font Navigator Group File |
| FNK | FunkTracker Module Format |
| FNT | Font File |
| FO1 | Borland Turbo C Font |
| FO2 | Borland Turbo C Font |
| FOB | Navision Financials Object |
| FOG | Fontographer Font |
| FOL | 1st Reader Saved Message Folder |
| FON | Font File |
| FON | Telix Telephone Book Database |
| FON | Procomm Plus Call Log |
| FOO | Kai's SuperGoo Fusion |
| FOR | WindowBase Database Form |
| FOR | Fortran Source |
| FOT | TrueType Font |
| FOX | FoxPro+ Compiled Program |
| FP | FoxPro INI |
| FP | FileMaker Pro File |
| FP1 | Flying Pigs for Windows Data |
| FP3 | FileMaker Pro File |
| FP5 | FileMaker Pro Document |
| FPC | FoxPro Catalogue File |
| FPF | FilterPro active filter design program from Texas Instruments |
| FPM | FoxPro startup file |
| FPQ | FoxPro Database Query |
| FPT | Farandole Composer Pattern Sound |
| FPT | Microsoft FoxPro Memo Fields |
| FPT | FileMaker Pro File |
| FPW | FloorPlan Plus Floorplan Drawing |
| FPW | FoxPro for Windows Configuration |
| FPX | FlashPix Bitmap |
| FPX | Compiled FoxPro program |
| FR3 | dBase IV Renamed dBase III+ Form |
| FRA | FrameViewer File |
| FRF | FontMonger Intermediate Font |
| FRG | dBase IV Uncompiled Report |
| FRL | FormFlow File |
| FRM | FrameMaker or FrameBuilder Document |
| FRM | Clipper, dBase, dBFast Database Report |
| FRM | WordPerfect Merge Form |
| FRM | Form File (Visual Basic and others) |
| FRM | Datacad Symbol Report File |
| FRM | Oracle Executable Form |
| FRO | dBase IV Compiled Report |
| FRO | FormFlow File |
| FRP | PerForm Pro Plus Form |
| FRS | WordPerfect Graphics Driver |
| FRT | FoxPro Report File |
| FRX | Visual Basic Binary Form File |
| FRX | FoxPro Report File |
| FRZ | FormFlow File |
| FSF | fPrint Audit Tool File |
| FSF | Convert It! Factor File |
| FSH | EA Sports Game Graphic Editor File |
| FSL | Borland's Paradox 7 Forms |
| FSL | Corel Paradox Saved Form |
| FSM | Farandoyle Sample Format |
| FSS | Iomega Backup File Selection Set |
| FST | dBFast Database Program |
| FST | FastStats Analyzer File |
| FSX | Lotus 1-2-3 Data |
| FT | Lotus Notes Full Text Index |
| FTB | Roots3 Index File |
| FTG | Windows Help Full-text Search Group File |
| FTL | FutureTense Texture |
| FTM | WinFax Pro |
| FTM | Family File |
| FTM | Micrografx Font |
| FTS | Windows Help Full-Text Search Index File |
| FTS | Flexible Image Transport Systems image |
| FTV | Forest & Trees File |
| FTW | Family File |
| FW | Framework Database |
| FW2 | Framework II |
| FW3 | Framework III |
| FW4 | Framework IV |
| FWB | FileWrangler Data File Backup |
| FWL | FileWrangler EXE Library |
| FWS | FileWrangler Data File for File Splitting Configuration |
| FX | FastLynx On-Line Guide |
| FXD | FAXit Phonebook |
| FXD | WinFax Sent Document |
| FXD | FoxPro FoxDoc Support |
| FXI | File-Ex File |
| FXM | WinFax Pro document |
| FXO | Fax Image Document |
| FXP | FoxPro Compiled Source |
| FXR | WinFax Received Document |
| FXS | WinFax Fax Transmit Graphic |
| FZB | Casio FZ-1 Bank Dump |
| FZF | Casio FZ-1 Full Dump |
| FZV | Casio FZ-1 Voice Dump |