| MATHEMA Software GmbH | Bavaria |
| Mathematisches Forschungsinstitut Oberwolfach gGmbH | Baden-Württemberg |
| Matheretter | Berlin |
| Mathias Harbeck | Hamburg |
| Matoma Internet Consulting GmbH | Baden-Württemberg |
| Matrix One | |
| Matrix Technology GmbH | |
| MATRIX-Computer GmbH | Bavaria |
| Matrix42 | Hesse |
| Matronic GmbH & Co. Electronic Vertriebs KG | Baden-Württemberg |
| Matterway | |
| Matthias Brück | |
| Matti Maier | Baden-Württemberg |
| MATUSCH GmbH | Bavaria |
| Maus Click Werbeagentur GmbH | |
| Mauve | North Rhine-Westphalia |
| Mauve Mailorder Software GmbH & Co KG | North Rhine-Westphalia |
| Maviance GmbH | |
| MAX Automation SE | |
| Max Delbrück Center for Molecular Medicine in the Helmholtz Association | |
| Max Planck Institute for Informatics | |
| Max Planck Institute for Mathematics | |
| Max Planck Institute for Software Systems | |
| Max R. Scheer aka Rutiso | Berlin |
| Max Systeme GmbH | Saxony |
| Max-Born-Institut im Forschungsverbund Berlin e.V. | |
| Max-f IT Solutions | Baden-Württemberg |
| Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. | |
| Max-Planck-Innovation GmbH | |
| Max-Planck-Institut für Herz-und Lungenforschung W.G. Kerckhofff-Institut | |
| Maxco-Computer Hard u. Software | Lower Saxony |
| Maximilian Held | |
| Maximilian Weber | |
| MAXON Computer GmbH | Hesse |
| Maxpert AG | Hesse |
| MAXQDA | Berlin |
| MAXXmarketing GmbH | Bavaria |
| May Computer-Service | |
| May Ventures Management GmbH | |
| Mayflower GmbH | Berlin |
| Mazy Systems | Berlin |
| mb AEC Software GmbH | Rhineland-Palatinate |
| MB Computer-Spezialist GmbH | North Rhine-Westphalia |
| MB Connect Line GmbH | |
| MB Electronic AG | Bavaria |
| mb Systemhaus GmbH | North Rhine-Westphalia |
| MB-IT GmbH | Lower Saxony |
| mb-systems | |
| MBFG GmbH & Co. KG | Baden-Württemberg |
| MBG Mittelständische Beteiligungsgesellschaft Baden-Württemberg GmbH | |