| xet | X-Genics eManager Process Definition |
| xev | X-Genics eManager Auto-Update File |
| xez | X-Genics eManager Template Package |
| xfb | LonWorks Binary Device Interface File |
| xfc | Origin Compiled X-Function File |
| xff | NiceLabel Form Data |
| xfo | LonWorks Optimized Device Interface File |
| xfr | TIBCO iProcess Process Definition |
| xft | Adobe Form Designer XML Form Template |
| xfz | Declan Flashcards Words Data |
| xg0 | Corel Paradox Index File |
| xg1 | Corel Paradox Index File |
| xhb | HomeBank Data File |
| xhp | OpenOffice.org XML Help |
| xic | DIF Freedom Data |
| xid | Visual Localize XML Import Definition |
| xif | LonWorks Device Interface File |
| ximp | XOS Digital Export Package |
| xip | Photo Mechanic Metadata File |
| xir | XML Intermediate Representation Data |
| xix | Microsoft IIS NNTP Subject Lists |
| xkb | X Keyboard Extension Data |
| xle | XML Cooktop File |
| xlg | Autodesk AutoCAD XREF Log File |
| xlgc | Prosystech ExpressK Database |
| xli | 3D Studio Max IGES Input Log |
| xln | Excellon Drill File |
| xlo | 3D Studio Max IGES Output Log |
| xlo | Autodesk Inventor Export Journal |
| xlog | XLOG XML Log |
| xlp | SAP BO Xcelsius Add-On Package Project |
| xlx | SAP BO Xcelsius Add-On Package |
| xlz | Crossword Power Tools Crosswords Library |
| xmbl | Vernier Logger Pro Data |
| xmc | Expression Media Catalog |
