| wtr | SimSig WTT Timetable Rules |
| 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 |
| wwd | Microsoft Works Wizard Data |
| wwf | WAsP Wind Farm Data |
| wwg | CARE-S InfoWorks Wastewater Data |
| wwh | WAsP Workspace |
| wwi | WinWein Interchange Format Data |
| wwk | WAsP v7 Workspace |
| wwls | Weather Watcher Live Skin |
| wwq | SWAT Watershed Water Quality Input |
| wwr | WAsP v8 Resource Grid |
| wwtfig | WorldWide Telescope Constellation Figures Data |
| wwtl | WorldWide Telescope Layer Data |
| wwu | Wwise Work Unit |
| wxp | wxWidgets Package Description Data |
| wxw | Winradio Extended Wave Data |
