| Abbreviation | Definition |
|---|---|
| MCL | Modern and Classical Languages |
| MCML | Media Center Markup Language |
| MCML | Music Contents Markup Language |
| MCW | Michener Center for Writers |
| MDAL | Music Data Abstraction Language |
| MDDL | Market Data Definition Language |
| MDDL | Medical Device Data Language |
| MDIL | Machine Dependent Intermediate Language |
| MDUL | Modular Data Unit Language |
| MDWG | Mirima Dawang Woorlab-Gerring (Federation of Aboriginal and Torres Strait Islander Languages; Kununu |
| MEDL | Meta Event Definition Language |
| MELAB | Michigan English Language Assessment Battery |
| MELD | Mainstream English Language Development |
| MELP | Minnesota English Language Program |
| METL | Message Element Type Language |
| MF | Me First |
| MFL | Message Format Language |
| MFL | Modern Foreign Language |
| MFLA | Maryland Foreign Language Association |
| MFLA | Massachusetts Foreign Language Association |