| mgf | Materials and Geometry Format Data |
| mgf | Minitab Graph Data |
| mgh | MGH MRI Data |
| mgi | Magellan eXplorist Geocache Waypoint Data |
| mgi | Magellan eXplorist Map Image |
| mgjson | Adobe After Effects Motion Graphics JSON Data |
| mgm | Equation Illustrator Macro |
| mgn2 | Bloody Mouse Macro Data |
| mgo | MacGourmet Recipe |
| mgp | Adobe Captivate Menubuilder Data |
| mgrp | NI Maschine v1 Group Data |
| mgrs | Military Grid Reference System Data |
| mgspot | MacGourmet Spotlight MetaData |
| mgt | SWAT Management Input Data |
| mgtheme | MacGourmet Theme |
| mgw | Microgateway Policy Implementation Data |
| mgz | Compressed MGH MRI Data |
| mhd | ITK MetaImage Header |
| mhe | Hackshield Heuristic Engine File |
| mhg | MHEG-5 Multimedia Data |
| mhl | Media Hash List |
| mhm | Microsoft Mouse and Keyboard Center Macro |
| mhp | Maths Helper Plus Data |
| mhr | OpenAL Soft HRTF Data |
| mhs | Xilinx Microprocessor Hardware Specification |
| mhtmlenx | Egis Encrypted MHTML Data |
| mi | Mental Ray Scene |
| mi2 | AutoDesk Softimage Data |
| mia | Autodesk Softimage Object Render Archive |
| miaf | InstallAware Setup Dialog Rules |
