| xmat | Exient XGS Shader Material Data |
| xmcf | FileMaker Pro Custom Function Data |
| xmla | XML for Analysis File |
| xmlc | ASP.NET Compiled XML |
| xmljet | Eclipse JET XML Template |
| xmlo | FileMaker Pro Layout Object Data |
| xmta | Visual Studio Design-Time Attribute Data |
| xn | Cygwin LD-Script Data |
| xnb | XNA Game Studio Binary Package |
| xnd | exNode Download Data |
| xob | WeintekHMI EasyBuilder 8000 XOB File |
| xojo_binary_menu | Xojo Binary Menu Data |
| xojo_binary_project | Xojo Binary Project |
| xojo_binary_toolbar | Xojo Binary Toolbar Data |
| xojo_binary_window | Xojo Binary Window Data |
| xojo_menu | Xojo Menu Data |
| xojo_project | Xojo Project |
| xojo_toolbar | Xojo Toolbar Data |
| xojo_window | Xojo Window Data |
| xojo_xml_menu | Xojo XML Menu Data |
| xojo_xml_project | Xojo XML Project |
| xojo_xml_toolbar | Xojo XML Toolbar Data |
| xojo_xml_window | Xojo XML Window Data |
| xol | Sybase PowerDesigner Object Language Data |
| xoml | Microsoft Visual Studio Windows Workflow |
| xpb | XPB! Basic Source Code |
| xpk | Xscript Package |
| xpp | X++ Source Code |
| xpz | GeneXus Object |
| xq | XQuery Language Source Code |
