| Abbreviation | Definition |
|---|---|
| MES | WordPerfect Library Macro Editor work space file |
| MET | Document (Omnipage Pro) |
| MET | Graphics metafile (OS/2) |
| MET | Macro Editor top overflow file (WordPerfect Library) |
| MET | Metafile (OS/2) |
| MEU | DOS Shell Menu group |
| MEX | Dynamically linked subroutines (Macintosh) (Matlab) |
| MEX | Macro Editor expound file (WordPerfect Library) |
| MEX4 | Matlab Dynamically linked subroutines |
| MEXDS | Dynamically linked subroutines (DECStation) (Matlab) |
| MEXHP3 | Dynamically linked subroutines (HP9000/series 300) (Matlab) |
| MEXHP7 | Dynamically linked subroutines (HP9000/series 700) (Matlab) |
| MEXN | Dynamically linked subroutines (NeXT) (Matlab) |
| MEXRS6 | Dynamically linked subroutines (IBM RS/6000) (Matlab) |
| MEXSG | Dynamically linked subroutines (SGI) (Matlab) |
| MF | TeX Metafont text file |
| MF4 | Measurement File format version 4 |
| MFD | Monadic functions (ABC programming language) |
| MFJ | MetaFont job (batch input) |
| MFM | Music format (DMP) |