| mcmc | MrBayes MCMC Data |
| mcml | Windows Media Center Markup Language File |
| mcp | Amiga MUI Preference Class Data |
| Mathcad Printer Driver |
| Megacubo Package |
| mcpr | Minecraft Replay Mod Replay |
| mcr | Autodesk 3D Studio Max Macroscript |
| BricsCAD Macro Data |
| CuteFTP Script |
| General CADD Macro |
| Macro ToolsWorks Macro Data |
| MCreator Workspace |
| Perfect Keyboard Macro |
| RSView Machine Edition Macros Data |
| Tecplot 360 Macro Data |
| mcreator | MCreator Workspace |
| mcs | HalfLife MapCycle Editor Data |
| Intel MCS-86 Hexadecimal Object |
| Mathcad Image Data |
| Maximal Compressed Structure |
| Pro/ENGINEER ModelCheck Start Configuration Data |
| mcsg | MagicaCSG 3D Model |
| mcsv | TouchGraph Navigator MCSV File |
| mct | Live Messenger Content |
| MapChart Genetic Map Data |
| 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 |
| Moneydance Financial Data |
| Sega Genesis ROM MD |
| Sharkport Saved Game |
| Technics SX-KN6000 User MIDI Settings Data |
| md0 | Adobe Photoshop Metadata Cache |
| md03 | Macromedia Director Data |
| md2p | MessengerDiscovery M2DP Data |
| md2s | MessengerDiscovery Data |
| md5 | MD5 Checksum |
| md5sum | MD5 Checksum |
| md5sums | MD5 Checksum |
| md93 | Macromedia Director 4 Data |
| md95 | Adobe Director for Mac Data |
| mdat | REW Measurement Data |
| mdb | Autodesk PartMaker Materials Database |
| Nastran Modal Database |
| Pro/MECHANICA Database |
| RockWorks Borehole Database |
| mdbx | Microsoft Access JET Database |
| mdc | Cognos Cube File |
| mdccache | Microsoft Document Connection Cache Data |
| mdcs | MATLAB Distributed Computing Server Saved Session |
| mdd | BSL MDD Data |
| MDict Resource Data |
| Notation Composer Midi Device Description |
| Point Oven Deformation Data |
| Quanquest SPSS Questionnaire Definition Data |
| Xilinx Microprocessor Driver Description |
| mde | ArchiCAD Education Module File |
| mdef | ANSYS Workbench Managed Data |
| mdex | Mifos Data Exchange XML Data |
| MIRCaM Data EXchange File |
| mdf | I-DEAS Master Drafting Machine Data |
| Insight II Molecular Data |
| Microsoft SQL Server Database |
| RSView Machine Edition Data Log Model |
| SDL Trados Studio Translation Memory Data |
| mdg | DG Kernel Model Data |
| Enterprise Architect Data |
| myPM Merge Data |
| Transformation Extender Map Debug Data |
| mdif | EEsof Model MDIF File |
| mdimporter | Mac OS X Spotlight Importer Settings Data |
| mdinfo | iPhone Backup Information Data |
| mdist | PLINK Genomic Distance Proportion Matrix Data |
| mdk | Astra Schedule Schedule Data |
| mdl | Animation Master Model Data |
