| msn | MSN Content Plus Installation Data |
| msnbak | MSN Mail Backup Data |
| mso | Microsoft Office Rendering Data |
| msof | Microsoft Office for Mac Data |
| msor | FiberTrace Data |
| msp | ClarisWorks Dictionary Data |
| msp | Technics SX-KN6000 Manual Sequence Pads Data |
| mspdi | Microsoft Project XML Data Interchange File |
| mspj | Microsoft Project for Mac Data |
| mspm | Nanoeducator File |
| msq | LightShow Pro Media Sequence |
| msr | Mail.dat Manifest Summary File |
| mss | CartoCSS Map Stylesheet |
| mss | MediaShout Presentation Script |
| mss | Microprocessor Software Specification |
| mss | WRAP Message Data |
| mssp | mIRC Script Setup Creator Data |
| msstyle | Windows XP Unsigned Style |
| msstyles | Windows XP Style Data |
| mst | ChemFinder Chemical Structure Index Data |
| mst | Corel Presentations Master Template |
| mst | Gurobi Optimizer MIP Start Data |
| mst | Microsoft Visual Test Source Code |
| mst | Microsoft Windows Installer Transform |
| mst | Pension System Master Data |
| mst | Room Arranger Project |
| mst | Steam Client Installer Transform Data |
| mstat | SAM Domain Output Data |
| mstr | MicroStrategy Dashboard Data |
| mstt | Prosa Minispecification Data |
