| wscx | Wondershare SurveyCreator Data |
| wsdt | IAR Embedded Workbench Workspace Settings |
| wset | Microsoft Word for Mac Settings Data |
| wspos | IAR Embedded Workbench Window Placement Data |
| wst | WinSSHD Settings |
| wtc | WaveThunder Configuration Data |
| wti | WebTranslateIt Configuration |
| wtp | Word2TeX Preferences |
| wusikprst | Wusikstation Preset Data |
| wxa | Buxco System Hardware Configuration Data |
| wxpr | Wax Preset Data |
| wzc | AbleCommerce Wizard Configuration Data |
| wzconfig | WinZip Configuration |
| wzz | HyperPublish Wizard Settings Data |
| x4k | XML4King Configuration |
| xaw | Xilinx ISE Architecture Wizard Settings Data |
| xbs | XnConvert Configuration |
| xc | RSNetWorx Configuration |
| xces | PDF-XChange Editor Settings Data |
| xci | Adobe LiveCycle Font Mapping Data |
| xconf | PTC Windchill Configuration |
| xcu | OpenOffice.org Configuration File |
| xee | Microsoft Expression Encoder Preset |
| xep | X-Genics eManager File Packaging Information |
| xfitrc | XtalView Xfit Configuration Data |
| xfsf | BestSync Settings Data |
| xgc | GtkRadiant XML Game Config |
| xgi | XBCD Custom Settings File |
| xgs | XACT Global Settings |
| xiu | Chiasmus Configuration |
| xjb | JAXB Binding Customization |
| xjs | Jindent Settings File |
| xly | CMUD Settings Data |
| xmbclp | X-Mouse Button Control Data |
| xmbcs | X-Mouse Exported Settings Data |