| mailloc | Mac OS X Finder Mail Internet Location |
| mailstationery | Apple Mail Stationery Data |
| mailtoloc | Mac OS X Finder Mail Internet Location |
| mailview | Microsoft Mail View Data |
| main | FileMaker Pro Dictionary Data |
| maj | CAMduct Job Data |
| maker | Adobe FrameMaker Data |
| mal | RSView Machine Edition Alarms Data |
| mamc | Auto Mouse Click Script |
| maml | Microsoft Assistance Markup Language Data |
| mamp | MAMP Related Data |
| man | AquaCrop Field Management Data |
| Blaise Manipula Setup Data |
| Windows Mandatory User Profile Data |
| manifest | Steam Manifest Data |
| map | 3Com Network Supervisor Network Map |
| BrainVoyager QX Map Data |
| EspressReport Map Data |
| Hex Workshop Character Map |
| IBM Sterling B2B Integrator Map Source |
| Ingres Termcap Mapping Data |
| Leadwerks Map Data |
| Map Data |
| Mapjects Server Webparts Data |
| Micrografx Picture Publisher Image Map Data |
| NI REAKTOR Wavetable Data |
| Offline Explorer Map Data |
| Poser 3D Map Data |
| Pro/ENGINEER Map Data |
| Rigs of Rods Key Assignments Data |
| TECkit Mapping Table |
| WAsP Terrain Map |
| Weather Defender Map Data |
| map16 | SNES Map16 Tile Data |
| maplet | Maple Maplet File |
| maplib | Mscape Map Data |
| mapx | MapDotNet UX Map File |
| Mapjects Client Webparts Data |
| mar | Pegasus Mail Attribute Record Data |
| marcxml | MARC 21 XML Schema Data |
| marker | Microsoft Windows 10 System Data |
| markers | BEAGLE Markers Data |
| marm | EPOC Makefile for MARM Platform |
| marshal | Marshal Data Migration Model |
| mas | MEGA Alignment Sequence Data |
| mascot | Otaku Mascot Mascot Data |
| mash | Java Mashing Data |
| mask | Adobe SpeedGrade Color Mask |
| ImageMagick Mask Data |
| mat | Altair FEKO Matrix Element Data |
| Animation Master Material Data |
| Autodesk 3D Studio Max Material Data |
| Bryce 3D Material Data |
| CRiSP Harvest Maturation Data |
| CX-Supervisor Library Data |
| Gretl Text Data |
| Kerkythea Material Data |
| MODELLER Matrix Data |
| Ox Matrix Data |
| PLS-POLE Material Data |
| Poser 3D Material Data |
| Pro/ENGINEER Material Properties Data |
| V-Ray Material Data |
| Vue Material Data |
| material | Rigs of Rods Texture Reference |
| math | AnalyticMath Data |
| matl | Sonnet Substrate Data |
| matplot | Matplotlib Plot |
| matte | Gimp Matte Data |
| matx | eXtendable Wad Editor MATX Data |
| mauve | Mauve Alignment Data |
| max | Action Replay Max Save File |
| BSL Image Maximum Values Data |
| maxa | MAXA Crypt Mobile Encrypted File |
| maxc | Autodesk 3D Studio MAX Container |
| maxd | PaperPort Annotation Data |
| maxfr | MaxView Web Pointer Data |
| maxm | PaperPort Data |
| maz | dVISE 3D Model |
| mb | Corel Paradox Memo Holder Data |
