| xtu | Intel Extreme Tuning Utility Data |
| xtx | Xtext Data |
| xtxt | Xtext Data |
| xui | Xbox 360 User Interface Data |
| xule | XBRL Rules Data |
| xulrunner | XULRunner Data |
| xum | Excel CAPE-OPEN Unit Operation Model Data |
| xur | Xbox 360 User Interface Binary Data |
| xus | UpdateStar Data |
| xvas | eXtendable Wad Editor XVAS Data |
| xvg | Grace Document |
| xvo | RatDVD Internal Data |
| xvp | XView Package |
| xvrml | eXtensible Virtual Reality Modeling Language Format Data |
| xvs | XView Scene Package |
| xvu | Comodo BOClean Definitions |
| xvv | Placevent 3D-RISM Results Data |
| xvw | MAPublisher View Data |
| xwav | eXtendable Wad Editor XWAV Data |
| xwdf | VooPoo Firmware Update Data |
| xwlt1 | eWallet GO! Backup Data |
| xws | Crossware Embedded Development Studio Workspace Data |
| xwz | X-Setup Pro Wizard Data |
| xx | Xxencoded Data |
| xx2 | GE Solar 8000M Data |
| xxd | Brixx Planner Calendar Data |
| xxe | Xxencoded Data |
| xxi | GameSpy Arcade Data |
| xxl | Xilog Plus XXL File |
| xxr | Brixx Planner Report Data |
| xxs | StruMM3D Structure Data |
| xxx | MTFLOW Geometry Data |
| xxx | Singer XL Embroidery Data |
| xy | ALEID2000 Coordinates Data |
| xy | Green Kenue XY Data |
