| WM | Windows Media A/V File |
| WMA | MS Active Streaming (Media) File |
| WMC | WordMarc Document |
| WMC | WordPerfect Macro |
| WMD | Windows Media Download File |
| WMF | Windows Metafile |
| WML | Wireless Markup Language File |
| WMP | Windows Media Player File |
| WMS | Windows Media Skin File |
| WMV | MS Active Streaming (Media) File |
| WMX | Audio Playlist |
| WMX | Windows Media Player A/V Shortcut |
| WMZ | Windows Media Compressed Skin File |
| WN | Write Now Text File |
| WND | WinG Hidden Palette Task |
| WNF | Corel Outline Font |
| WOA | Windows Swap File |
| WOC | Organisation Chart |
| WOR | MapInfo Workspace |
| WOW | Grave Composer Music Module |
| WP | WordPerfect Document |
| WP4 | WordPerfect 4 Document |
| WP5 | WordPerfect 5 Document |
| WP6 | WordPerfect 6 Document |
| WP7 | WordPerfect 7 Document |
| WP8 | WordPerfect 8 Document |
| WPC | Windows 95 WordPad file converter |
| WPD | WordPerfect Screen Driver or Document |
| WPD | 602 pro PC SUITE Document File |
| WPF | Informs form |
| WPF | WorldPort Fax |
| WPF | Enable Word Processing Document |
| WPG | WordPerfect/Drawperfect Graphics |
| WPJ | Make Project |
| WPK | Keyboard |
| WPK | WordPerfect Macros |
| WPM | WordPerfect Macro |
| WPM | WordPerfect for Apple Macintosh Document |
| WPS | Microsoft Works Document |
| WPT | WordPerfect Document Template |
| WPW | Novel PerfectWorks Document |
| WPX | Adobe Printer Description |
| WQ! | Compressed Quatro Pro Spreadsheet |
| WQ1 | QuattroPro/DOS Spreadsheet |
| WQ2 | QuattroPro/DOS version 5 Spreadsheet |
| WR1 | Lotus Symphony Spreadsheet File |
| WRD | Charisma Template |
| WRF | WebEx Recording |
| WRI | Write Document |
| WRK | Lotus Symphony 1, 1.01 Spreadsheet |
| WRK | Cakewalk Music Project File |
| WRL | Virtual Reality Model |
| WRL | Plain Text VRML File |
| WRP | Amiga Warp Archive |
| WRS | WordPerfect Windows Printer Driver |
| WRX | Progress Database File |
| WRZ | GNUZIP Compressed VRML File |
| WS | WordStar Document |
| WS1 | WordStar for Windows 1 Document |
| WS2 | WordStar for Windows 2 Document |
| WS3 | WordStar for Windows 3 Document |
| WS4 | WordStar for Windows 4 Document |
| WS5 | WordStar for Windows 5 Document |
| WS6 | WordStar for Windows 6 Document |
| WS7 | WordStar for Windows 7 Document |
| WSC | Windows Script Component |
| WSD | WordStar 2000 Document |
| WSE | Wise File |
| WSF | Windows Script File |
| WSH | Windows Script Host Settings File |
| WSL | Lotus Fast-Site smart master |
| WSP | Workspace Information (Microsoft Visual C++, Fortran, 16-bit versions) |
| WSQ | Wavelet-packet Scalar Quantisation |
| WSP | Workspace (various) |
| WST | WordStar Document |
| WSX | WinMX Filesharing Program |
| WSZ | WinAmp Skin Zip File |
| WT2 | WordExpress Document Template |
| WTA | WinTune DLL |
| WTD | WinTune Document (Database of test results, binary) |
| WTX | WinTune Export Document (results of one test, text) |
| WVL | Wavelet Compressed Bitmap |
| WW4 | WinWhatWhere User Activity Log |
| WWB | WordPerfect Button Bar |
| WWK | WordPerfect Keyboard Layout |
| WWL | Microsoft Word Add-in File |
| WWP | Microsoft Works for MS-DOS Document |
| WWS | AutoRoute User Information |
| WZD | Sharp Organizer Program or Data File |
| WZS | Wizard |
| WZN | WhizFolder Document |