| msy | MicroSyn Data |
| msz | MediaMonkey v3 Compressed Skin |
| mt5 | Poser Material Data |
| mt940 | SWIFT MT940 Customer Statement Message |
| mta | Samsung AllShare Metadata |
| mtb | Minitab Exec File |
| mtbl | PIPE-FLO Motor Data Table |
| mtc | BrainVoyager QX Mesh Time Course Data |
| mtf | SDL Trados Translation Memory Translations |
| mtg | Making the Grade Data |
| mth | Derive Math File |
| mtkey | proDAD Heroglyph License Data |
| mtn | PTC Creo Tool Motion Parameter Data |
| mto | FastCAM MTO Data |
| mtp | SpectraMagic NX Template |
| mtst | MotionTracking RAW Image Stack Data |
| mtt | FastCAM MTO Data Template |
| mtt | MetadataTouch Template |
| mtu | Match! User Database |
| mtw | Minitab Worksheet |
| mub | ExtractNow Data |
| muc | Music Collector Collection Data |
| mucow | Adobe Muse Configurable Options Widget |
| mud | Textease Database CT Multi-user Database |
| mudp | Active Safety System Internal Log |
| mulib | Adobe Muse Widget Library |
| mult | SAM Multiple Domain Alignment Output |
| murl | Maxthon Browser URL Data |
| musx | Minâ€Uâ€Script Xpress Data File |
| mvf | Autodesk AutoFlix Animation Data |
| mvhlink | MyVirtualHome Link Data |
| mvi | Autodesk AutoCAD AutoFlix Movie Command File |
| mvl | Medison Ultrasound 3D Volume Data |
| mvm | MAGIX PhotoStory Slideshow |
| mvr | IBM HotMedia Multimedia Data |