| xrl | Concordance Markup Data |
| xrl | OSCAR Rules Data |
| xrl | Rapidform XOR 3D Scan CAD Data |
| xrl | Sybase PowerDesigner Report Language Data |
| xrm-ms | Windows Vista Activation Certificate |
| xrnt | Renoise DSP Device-chains Data |
| xrr | Chiron NRG Runtime Report Data |
| xrt | Revolution Single-spectrum Xraytor Data |
| xry | XRY Data |
| xrz | AiM Tech EVO4S Logger Data |
| xs | Hummingbird Exceed Startup File |
| xsb | Sybase PowerDesigner XML Model Backup |
| xsb | XMLBeans XML Schema Binary |
| xsbz | Oracle BI Publisher Sub Template |
| xsc | RFM Molecule Cross-Section Data |
| xsd | MAPublisher Custom Coordinate System Data |
| xsdif | Altova DiffDog Schema Data |
| xse | EQuIS Data Processor Format Definition Data |
| xseq | xLights Sequence Data |
| xsf | IMVU Skeleton Data |
| xsf | Xilinx CORE Generator Pin File |
| xsi | Softimage dotXSI 3D Model |
| xsiaddon | Softimage dotXSI Add-on |
| xsig | eCoFirma XAdES Signature Data |
| xsk | XKeyBrew Menu Data |
| xsm | Sybase PowerDesigner XML Model |
| xsn | xyAlgebra Data |
| xso | XKeyBrew Menu Data |
| xsp | MAPublisher XSP Data Source |
| xsprl | X-Setup Pro Data |
| xsprla | X-Setup Pro Data |
| xsr | Bentley GEOPAK XS List Report |
| xsr | Tekla Structures FabTrol Report |
| xss | Microsoft SharePoint WorkSpace Groove Database |
| xssz | Oracle BI Publisher Style Template |
