| mpb | Music Publisher Backup File |
| mpcatalog | Phase One Media Pro Catalog |
| mpcb | ReliaSoft MPC Data |
| mpd | Xilinx Microprocessor Peripheral Definition |
| mpd | Microsoft Project Database |
| mpdb | Windows Media Player 12 Database |
| mpex | Mass Properties Exchange Data |
| mpgindex | Adobe Premiere Mpeg Index |
| mph | COMSOL Multiphysics Data |
| mpi | Moldflow Plastics Insight Document |
| mpk | Project64 Memory Pack |
| mpl | Maple Language File |
| mpl | AVCHD Playlist Data |
| mpls | Blu-ray Disc Movie Playlist |
| mpu | Mail.dat Mail Piece Unit File |
| mpw | Mapwel GPS Map |
| mpz | MADRIX 3 Compressed Patch |
| mq | Microsoft Windows Message Queuing Data |
| mqb | Metasequoia Brush File |
| mqd | Malete Query Data File |
| mqm | Metasequoia Material File |
| mqo | Metasequoia Object File |
| mqp | Metasequoia Palette File |
| mqu | GraphicUSB Capture Data |
| mqx | Malete Query Access File |
| mqxliff | memoQ XLIFF Data |
| mr | Mapped Read Format Data |
| mrd | Malete Record Data File |
| mre | Steinberg MR Editor File |
| mrec | MADRIX Record File |
| mrf | Mapped Read Format Data |
| mrg | MySQL Merge File |
| mrk | Pro/ENGINEER Markup File |
| mrk | GP-Pro EX Mark Library |
| mrk | Kodak EasyShare Job Definition |
