| xlp | SAP BO Xcelsius Add-On Package Project |
| xlsbenx | Egis Encrypted Excel XLSB Document |
| xlsmenx | Egis Encrypted Excel XLSM Document |
| xlsxenx | Egis Encrypted Excel XLSX Document |
| xltbcd | XL Toolbox Chart Design Data |
| xlts | Umbraco Pro Data |
| xlx | SAP BO Xcelsius Add-On Package |
| xlz | Crossword Power Tools Crosswords Library |
| xm3 | Examiner Assessment Item Bank Data |
| xmat | 3dDeconvolve Design Matrix |
| xmbl | Vernier Logger Pro Data |
| xmc | Expression Media Catalog |
| xmdf | eXtensible Model Data Format Data |
| xmdl | XMDL Model |
| xmdx | ExamSoft SofTest Answer Data |
| xme | GME Metamodel |
| xmef | TextMap Evidence Format Data |
| xmf | IMVU 3D Model |
| xmfa | Mauve eXtended Multi-FastA Data |
| xmfd | FileMaker Pro XML Field Data |
| xmi | XMVB Input File |
| xmldsig | XML Digital Signature |
| xmlper | LeCroy Binary Waveform |
| xmlr | SiteScan XML Results |
| xmlz | ZennoPoster MP Template Data |
| xmm | Autodesk 3D Studio MAX XML Animation Map |
| xmmap | MindManager XML Map |
| xmmas | MindManager XML Theme Data |
| xmmat | MindManager XML Template |
| xmmmp | MindManager Map Part |
