| MARS | Developer | |
| MASA Group | Developer | |
| MAVERSSOFT | Developer | |
| MAVW | Developer | |
| MAXIMUMSPICY | Developer | |
| MAYHOW | Developer | |
| MAYO Games | Developer | |
| MAZ1k | Developer | |
| MAZAA | Developer | |
| MB | Publisher | |
| MBA International | Developer | |
| MBC Software | Publisher | |
| MBL Research | Developer | |
| MBoffin | Developer | |
| MC Lothlorien | DeveloperPublisher | |
| MC Lothlorien (Doug Anderson, Anthony Anderson, Paul Tonge) | Developer | |
| MC Lothlorien (John Atkinson, Anthony Anderson, Paul Tonge) | Developer | |
| MC Lothlorien (John Atkinson, Iain Traynor, Martin Holland) | Developer | |
| MC Lothlorien (John Atkinson, Martin Holland, Tiny Williams) | Developer | |
| MC Lothlorien (Paul Atkinson, Richard Joseph) | Developer | |
| MC Lothlorien (Peter Mannion, John Brennan, Iain Traynor) | Developer | |
| MC Lothlorien (R Lever, Martin Holland, Paul Tonge, Tiny Williams) | Developer | |
| MC Lothlorien (Tom Lanigan, Ed Knight) | Developer | |
| MC O'River (NA) | Publisher | |
| MC2 | Publisher | |
| MC2 France | Publisher | |
| MC2 FranceEU | Publisher | |
| MC2-Microids | DeveloperPublisher | |
| MC2-Microïds | Developer | |
| MCATIN | Developer | |
| MCF | DeveloperPublisher | |
| MCM Software | Publisher | |
| MCacique | Developer | |
| MCer4294967296 | Developer | |
| MD CyberBat | Developer | |
| MD Games | Publisher | |
| MD Software | Developer | |
| MD Software (Mevlut Dinc, Gary Thornton, Brian Marshall) | Developer | |
| MD Software (Mevlut Dinc, Gary Thornton, Jonathan P. Dean, Brian Marshall) | Developer | |
| MD Software (Mevlut Dinc, Jonathan P Dean, EM Dean, Nick Cook) Focus Creative Enterprises | Developer | |
| MDEV0 | Developer | |
| MDO | Developer | |
| MDickie | DeveloperPublisher | |
| MECC | DeveloperPublisher | |
| MEDER Dynamics | Developer | |
| MEDWARDS ART | Developer | |
| MEGA | Developer | |
| MEGA STUDIOS | Developer | |
| MEHARBA | Developer | |
| MELONKOI | Developer | |