| Abk. | Bedeutung | Kontext |
| M | Geldmenge | VWL |
| MAC | Media Access Control | IEEE 802 |
| MAPI | Messaging Application Programming Interface | Windows |
| MAPI | Machinery Allied Products Institute | BWL |
| MANIAC | Mathematical Analyzer Numerical Integrator And Computer | |
| MAP | Manufacturing Automation Protocol | |
| MAU | Multistation Access Unit | |
| MarkenG | Markengesetz | |
| Mars_NWE | Martin Stovers Netware Emulator | |
| MB | Megabyte | 1.048.576 Byte |
| MBPS | Millionen Bits Pro Sekunde | |
| MCF | Meta Content Framework | |
| MCIS | Microsoft Commercial Internet System | |
| MCSE | Microsoft Certified System Engineer | |
| MD | Message Digest | |
| MDE | Maschinendatenerfassung | |
| MDG | Minimum Delay Generator | Elektrotechnik |
| MDI | Multiple Document Interface | |
| MDStV | Mediendienste-Staatsvertrag | |
| ME | Mengeneinheit | |
| MEZ | Mittleeuropäische Zeit | |
| MFC | Microsoft Foundation Classes | |
| MFLOPS | Millions of Floating Point Operations per Second | |
| MHS | Mail Hub System | |
| MHz | Megahertz | |
| MIB | Management Information Base | |
| MIC | Media Interface Connector | |
| MIMD | Multiple Instruction Multiple Data | |
| MIME | Multipurpose Internet Mail Extension | |
| MIPS | Million of Instructions Per Seconds | |
| MIS-FET | Metall-Insulator-Semiconductor Feldeffekt-Transistor | |
| MISD | Multiple Instruction Single Data | |
| MIT | Massachusetts Institute of Technology | |
| MitbestG | Mitbestimmungsgesetz | |
| MM | Mitarbeitermonate | |
| MM | Manager Magazin | |
| MMF | Mail Message File | |
| MMS | Manufacturing Message Specification | |
| MNP | Mirocom Network Protocol | |
| MobIS | Modellierung betriebliche Informationssysteme | |
| MODEM | Modulate/Demodulate | |
| MOLI | Microsoft Online Institute | |
| MOS-FET | Metal-Oxide-Semiconductor Feldeffekt-Transistor | |
| MPM | Metra Potential Method | |
| MRP | Material Requirement Planning | |
| MRPII | Manufacturing Resurce Planning | |
| MS | Microsoft | |
| MSAU | Multistation Access Unit | |
| MSB | Most Significant Bit | |
| MSDL | Microsoft Download Library | |
| MSDN | Microsoft Developer Network | |
| MSFF | Master Slave Flipflop | |
| MSI | Medium Scale Integration | Elektrotechnik |
| MSN | Microsoft Network | |
| MSS | Management Support System | |
| MTA | Mail/Message Transport/Transfer Agent | |
| MTBF | Mean Time Between Failures | |
| MTS | Message Transfer System | |
| MUX | Multiplexer | |
| MVS | Multiple Virtual Storage | IBM, Betriebssystem |
| MwSt | Mehrwertsteuer | |
| MX | Mail Exchanger | |