| 11. | .mak | Project makefile |
| 12. | .mam | Macro shortcut (Microsoft Access) |
| 13. | .man | Formatted manual or reference page |
| 14. | .map | Color palette (colormap intensities and indices) ◊ Format data (Micrografx Picture Publisher) ◊ Geographical map (Atlas MapMaker) ◊ Linker map file ◊ Network map (AccView) |
| 15. | .maq | Query shortcut (Microsoft Access) |
| 16. | .mar | Archive (Microstation) ◊ Assembly program (VAX Macro) ◊ Report shortcut (Microsoft Access) |
| 17. | .marm | Makefile for MARM platform (EPOC) |
| 18. | .mas | Smartmaster set (Freelance Graphics) |
| 19. | .mass | Text document (Mass 11) |
| 20. | .mat | Matrix data file (Matlab) ◊ Table shortcut (Microsoft Access) ◊ geocoding matching parameters file (ArcView) |