| wscript | Waf Wscript |
| wsct | WinDev Test Scenario |
| wsdd | Axis Web Service Deployment Descriptor |
| wse | Wise Package Studio Script |
| wsi | Wise Package Studio Installer Package |
| wsil | Web Services Inspection Language Data |
| wsm | Wise Package Studio Merge Module |
| wsrc | WAIS Source File |
| wssp | CommuniGate Pro Web Server-Side Programming Data |
| wte | WinDev Report Template |
| wwn | WebDev Browser Procedures |
| wwt | WebDev Page Template |
| wxf | WinSQL Scheduled Task Script |
| wxi | WiX Include File |
| wxl | WiX Localization File |
| wxr | wxWidgets Resource Data |
| wxres | WinDev Automatic Test Results |
| wxs | WiX Source File |
| wxt | WinDev Automatic Test |
| x | XBLite Source Code |
| x | Microsoft DirectX D3D Object |
| xadl | XPLATFORM Application Program Definition |
| xal | Open XAL Configuration |
| xamlx | Visual Studio Workflow Service |
| xap | XACT Project File |
| xat | XAT Template |
| xbl | XBLite Source Code |
| xbml | SAP Business One Studio Workflow Process Data |
| xbw | SUP Hybrid Web Container Workflow |
| xcappdata | Xcode App Data |
