| xfb | LonWorks Binary Device Interface File |
| xfc | Origin Compiled X-Function File |
| xff | NiceLabel Form Data |
| xfg | FACSGen Face Data |
| xfi | xICE Desktop Encrypted 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 |
| xglc | EASE SpeakerLab GLL Configuration Data |
| xgmml | XGMML Graph |
| xgp | Xfire Game Patcher Data |
| xgpa | SC-NomadLAB Data |
| xhb | HomeBank Data File |
| xhf | NxOgre HeightField Data |
| xhn | EASE 4.0 ASCII Speaker Data |
| 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 |
| xit | SpatialAnalyzer Data |
| xit64 | SpatialAnalyzer Data |
| xix | Microsoft IIS NNTP Subject Lists |
| xjf | OmniPage BatchManager Job |
| xjsw | Tarsia Puzzle Data |
