| 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 | Macro ToolsWorks Macro Data |
| 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 |
| mct | MSN Messenger Packaged Flash Animation |
| mcu | Nokia DCT4 MCU Firmware Flash Data |
| mcv | ManyCam Effect |
| mcw | Monitor Calibration Wizard Data |
| mcx | MasterCook 5 Recipe Pictures |
| mcxe | MedicinesComplete Data |
| mcz | Poser Compressed Material Collection |
| md | Chaos Desktop Metadata |
| md | Sega Genesis ROM MD |
