| mcl | MCell Cellular Automata Data |
| mcl | MUSHclient World Information |
| mcl | SmartCAM Macro File |
| mcmac | MasterCook Mac Document |
| mcmc | MrBayes MCMC Data |
| mcml | Windows Media Center Markup Language File |
| mcp | Amiga MUI Preference Class Data |
| mcp | Mathcad Printer Driver |
| mcp | Megacubo Package |
| mcpr | Minecraft Replay Mod Replay |
| mcr | Autodesk 3D Studio Max Macroscript |
| mcr | BricsCAD Macro Data |
| mcr | CuteFTP Script |
| mcr | General CADD Macro |
| mcr | MCreator Workspace |
| mcr | Perfect Keyboard Macro |
| mcr | RSView Machine Edition Macros Data |
| mcr | Tecplot 360 Macro Data |
| mcreator | MCreator Workspace |
| mcs | HalfLife MapCycle Editor Data |
| mcs | Intel MCS-86 Hexadecimal Object |
| mcs | Mathcad Image Data |
| mcs | Maximal Compressed Structure |
| mcs | Pro/ENGINEER ModelCheck Start Configuration Data |
| mcsg | MagicaCSG 3D Model |
| mcsv | TouchGraph Navigator MCSV File |
| mct | Live Messenger Content |
| mct | MapChart Genetic Map Data |
| mcu | Nokia DCT4 MCU Firmware Flash Data |
| mcv | ManyCam Effect |
