| .mol |
MDL Molfile |
| .mqo |
Metasequoia Document |
| .mfil |
Blizzard Software Update File |
| .mode |
Coda Syntax Mode File |
| .module |
Drupal Module File |
| .msct |
MOPEKS Script File |
| .mthd |
MOPEKS Method File |
| .mtxt |
MOPEKS Text File |
| .miff |
Magick Image File |
| .mlm |
MolMeccano File |
| .mq5 |
MQL5 Source Code File |
| .mpws |
MathPiper Worksheet |
| .mjs |
ECMAScript Modules (ESM) files |
| .mac |
MacPaint Image |
| .m4u |
MPEG-4 Playlist |
| .master |
ASP.NET Master Page |
| .mq4 |
MQL4 Source Code File |
| .material |
Rigs of Rods Texture Reference File |
| .me2mod |
Mass Effect 2 Modification File |
| .mpdconf |
Music Player Daemon File |
| .mscx |
MuseScore Music Score File |
| .mgtheme |
MacGourmet Theme File |
| .mp7 |
Multisim 7 Project File |
| .mp9 |
Multisim 9 Project File |