| wsxz | SDL WorldServer WSXZ Package |
| wsz | WinAMP Skin |
| wt | WiredTiger Database Dump |
| wt4 | Win-Test Binary Log |
| wta | Tennis Navigator WTA Data File |
| wtb | Win-Test Binary Log |
| wtc | Wikitude Studio Image Collection Data |
| wtf | WinTaper Data File |
| wtg | WAsP Wind Turbine Generator Data |
| wth | CONTAM Weather Data |
| wtk | WinTalk URL |
| wtl | Windows Test Technologies Logger Results |
| wtml | WorldWide Telescope Collection Data |
| wto | Wikitude Studio Object |
| wtpl | WireTap Studio Library |
| wtr | SimSig WTT Timetable Rules |
| wtr | FARSITE Weather Data |
| wts | WebPlus Theme Set |
| wtt | SimSig WTT Timetable |
| wtx | WinTune Report |
| wu | Watchfire Bobby URL List |
| wud | Cast Soft wysiwyg User Data |
| wul | WinUHA Language Data |
| wup | WhatsUp Gold Network Map |
| wut | WUTG Tag Data |
| wvd | StarMoney Filter Data |
| wvf | Yokogawa Waveform Data |
| wvm | Ricardo WAVE Input |
| wvs | Wanvas Data |
| wvt | IDGS101 Waveform Data |
| wwa | WebSite-Watcher Archive |
| wwb | Corel WordPerfect Button Bar Data |
| wwf | WAsP Wind Farm Data |
| wwg | CARE-S InfoWorks Wastewater Data |
| wwh | WAsP Workspace |