| M-Ansley | Developer | |
| M-Beca | Developer | |
| M-INDUSTRIES | Developer | |
| M-OZO | Developer | |
| M-Tee | Developer | |
| M. | Developer | |
| M. B. Saunders | Developer | |
| M. Domin | Developer | |
| M. Hata | Developer | |
| M. KIRIN | Developer | |
| M. W. Bayley | DeveloperPublisher | |
| M. Wilcocks | Developer | |
| M.A. GUAX | Developer | |
| M.A. Starling | Developer | |
| M.A. Trace | Developer | |
| M.C. Game | Developer | |
| M.I.N | DeveloperPublisher | |
| M.Knight | Developer | |
| M.N.M Software | DeveloperPublisher | |
| M.R. Games | DeveloperPublisher | |
| M.S.T.O.P. | Developer | |
| M07 Games | DeveloperPublisher | |
| M0uftchup | Developer | |
| M151 Games | Developer | |
| M1lkslyvan | Developer | |
| M1sty | Developer | |
| M2 | DeveloperPublisher | |
| M23BobGames | Developer | |
| M2H | DeveloperPublisher | |
| M2H Game Studio | Developer | |
| M2tias | Developer | |
| M3D | Developer | |
| M4 Entertainment | Developer | |
| M4 Limited | Developer | |
| M4DG4M3R | Developer | |
| M5Altair | Developer | |
| M7md_Ark | Developer | |
| M7™ | Developer | |
| MAC | Developer | |
| MAC404 | Developer | |
| MACAMANDI | Developer | |
| MACDev | Developer | |
| MADEVIL Games | Developer | |
| MADIA Entertainment | Developer | |
| MADiSON Videogame | Developer | |
| MADia Entertainment | Developer | |
| MAHO! Studio | Developer | |
| MAK Computer Graphics | Developer | |
| MAK Computer Graphics (Mark A. Jones) | Developer | |
| MAMARRE_STUDIOS | Developer | |
| 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 | |
| MERJ Media | DeveloperPublisher | |
| MESSENGER | Developer | |
| META FOOL | Developer | |
| META Publishing | Publisher | |
| MEYOUMEYOU | Developer | |
| MEZZANINE | Developer | |
| MFatihMAR | Developer | |
| MG BEATZ | Developer | |
| MG Games | Developer | |
| MGAME Corp. | Developer | |
| MGC_Vlad | Developer | |
| MGFM | Developer | |
| MGI | Developer | |
| MGM Interactive | Publisher | |
| MGM Interactive, MGM | Publisher | |
| MGMasterco | Developer | |
| MGP Studios | Developer | |
| MGZone | Developer | |
| MGaia | Developer | |
| MGame Corporation | DeveloperPublisher | |
| MGibson | Developer | |
| MHP indie labs | Developer | |
| MHT Ingenieros | Publisher | |
| MIA | DeveloperPublisher | |
| MIC | DeveloperPublisher | |
| MICHE22 | Developer | |
| MICROS | Developer | |
| MIDI Vagrant | Developer | |
| MIDREKY | Developer | |
| MIG Entertainment | Publisher | |
| MIND MultiMedia | Developer | |
| MINIGOLIATH | Developer | |
| MISSING | Developer | |
| MIYAKOpubl | Developer | |
| MIchael Cinquegrano | Developer | |
| MJ | Developer | |
| MJ Child | Developer | |
| MJSama | Developer | |
| MK Smith | Developer | |
| MK Studios | Developer | |
| MK-ACT | Developer | |
| MKRTG | Developer | |
| MKRaw | Developer | |
| MLB | Developer | |
| MLB Advanced Media | DeveloperPublisher | |
| MLB.com | DeveloperPublisher | |
| MLBAM | Developer | |
| MLammF | Developer | |
| MLindblad | Developer | |
| MLoreley | Developer | |