XAR Corel Xara drawing

XLA Microsoft Excel add-in

XLB Microsoft Excel toolbar

XLC Microsoft Excel chart

XLD Microsoft Excel dialogue

XLK Microsoft Excel backup

XLM Microsoft Excel macro

XLS Microsoft Excel worksheet

XLT Microsoft Excel template

XLV Microsoft Excel VBA module

XLW Microsoft Excel workbook / workspace

XM FastTracker 2, Digital Tracker music module (MOD) file

XR1 Epic MegaGames Xargon data file

XTP XTree data file

XY3 XYWrite III document

XY4 XYWrite IV document

XYP XYWrite III Plus document

XYW XYWrite for Windows 4.0 document