| .m | Objective-C Language Source Format |
| .m!95 | Adobe Director For Mac |
| .m-jpeg | M-JPEG |
| .m01 | MicroStation Modification Resource |
| .m10 | Microsoft Money 2002 Data |
| .m11 | Microsoft Money 2003 Data |
| .m12 | Microsoft Money 2004 Data Format |
| .m13 | Microsoft Media Viewer |
| .m14 | Microsoft Media Viewer |
| .m15 | Apple QuickTime Format |
| .m16 | Microsoft Money 2007 Data |
| .m1a | MPEG-1 Audiostream Format |
| .m1c | IBM Voice Type Languages Newuser |
| .m1i | IBM Voice Type Languages Newuser |
| .m1pg | IFinish Video Format |
| .m1s | MPEG-1 System Stream |
| .m1v | Moving Pictures Experts Group Video (MPEG-1 IPB) |
| .m2 | World Of Warcraft Model Object File Format |
| .m21 | MPEG-21 Video Format |
| .m25 | Symantec Endpoint Protection Manager |
| .m2a | MPEG-2 Audio |
| .m2c | IBM Voice Type Languages Newuser |
| .m2d | HTC Manila 2D For Windows Mobile Skin |
| .m2dct | HTC Manila 2D For Windows Mobile Skin |
| .m2f | Maxthon Filter Package |
| .m2i | IBM Voice Type Languages Newuser |
| .m2l | Maxthon Language Package |
| .m2m | TiMidity++ M2M Settings |
| .m2p | MPEG-2 Stream File Format |
| .m2r | Avaya Mib2Rules Perl Script |
| .m2s | MPEG-2 Audio Video Format |
| .m2t | MPEG-2 Transport Stream Format |
| .m2ts | MPEG-2 Stream (Blu-Ray) |
| .m2u | Maxthon Layout |
| .m2v | MPEG-2 Packetized Elementary Stream |
| .m3 | Blizzard StarCraft 2 MDX3 Model Format |
| .m32 | Duke Nukem 3D Script |
| .m3c | IBM Voice Type Languages Newuser |
| .m3d | DIALux 3D Object Format |
| .m3g | Nokia Mobile 3D Graphics Program Format |
| .m3h | Starcraft 2 Model Data |
| .m3i | IBM Voice Type Languages Newuser |
| .m3s | Myst III Exile Saved Game |
| .m3t | Myst 3 Exile Text |
| .m3u | MP3 Songs Playlist Format |
| .m3u8 | UTF-8 M3U Playlist Format |
| .m3url | SMIL MP3 Playlist |
| .m3v | DJ Mix Pro Playlist |
| .m3x | MAGIX Digital Photo Maker PhotoCD Playlist |
| .m4 | M4 Preprocessor Macro Format |
| .m4a | MPEG-4 Compressed Audio Format |
| .m4b | MPEG-4 Audio Layer Audio Book Format |
| .m4c | IBM Voice Type Language Newuser |
| .m4d | Sage MAS 90 Data |
| .m4e | MPEG-4 Video Format |
| .m4f | Sony Network Camera MPEG-4 Video |
| .m4i | IBM Voice Type Languages Newuser |
| .m4l | Sage MAS 90 Data |
| .m4p | Apple ITunes Music Store Audio Format |
| .m4r | Apple IPhone Ringtone Format |
| .m4s | Myst IV: Revelation Save Game |
| .m4t | Sage MAS 90 Table |
| .m4u | MPEG-4 Playlist Format |
| .m4v | MPEG-4 Video File Format |
| .m51 | ARM Keil Tools Linker Listing |
| .m64 | Mupen64 Movie Capture |
| .m68 | Turbo Pascal Dos |
| .m75 | Apple QuickTime Format |
| .m7a | MapKing Map |
| .m7d | MapKing Navigation Map |
| .m7p | Multilizer PDF Translator Project |
| .m8 | Heretic II MipMap Image |
| .m?? | Ingres Modify Table/Index |
| .ma | Autodesk Maya ASCII Scene Format |
| .ma0 | Diablo II Act 1 Saved Map Progress |
| .ma1 | Monarch Audio Format |
| .ma1.mmf | SMAF Synthetic Music Mobile Application Format |
| .ma2 | Bibexcel |
| .ma2.mmf | SMAF Synthetic Music Mobile Application Format |
| .ma3 | Harvard Graphics Macro |
| .mab | Mozilla Address Book Format |
| .mac | MacPaint Bitmap Image |
| .maca | MacWrite Document |
| .macbin | MacBinary Archive |
| .macp | Apple Macintosh MacPaint Bitmap Image |
| .macs | MADRIX Encrypted Script |
| .mad | Microsoft Access Module Shortcut Format |
| .mae | Maestro Molecular Model Format |
| .maf | Microsoft Access Form Shortcut Format |
| .maff | Mozilla Archive Format |
| .mag | Microsoft Access Diagram Shortcut Format |
| .magic | Magic Mail Monitor Configuration |
| .magik | Magik Source Code Format |
| .mahjongtitanssave-ms | Mahjong Titans Save Game Format |
| .mai | Microsoft Mail Message Format |
| .maildb | MSN Mail |
| .mailhost | E-mail Server Preferences Format |
| .mailloc | Apple Mac OS X Finder Mail Internet Location |
| .mailplanelicense | Mailplane License Format |
| .mailstationery | Apple Mail |
| .mailtoloc | Apple Mail Mail Address Format |
| .main | FileMaker Dictionary |
| .maj | Camduct Job |
| .mak | Make Format |
| .make | Makefile |
| .makefile | Make Format |
| .maker | Adobe Framemaker |
| .maki | Winamp MAKI Compiled Script |
| .mako | Mako Tamplate Format |
| .mal | MadAppLauncher Settings Format |
| .mam | Microsoft Access Macro Shortcut Format |
| .maml | Microsoft Assistance Markup Language |
| .man | Unix Text Manual Format |
| .managed_manifest | Silverlight Manifest |
| .mani | Mine-imator Project Format |
| .manifest | Manifest Format |
| .manifest-desktop | Ubuntu Desktop CD Manifest |
| .manm | Vietcong Game Data Format |
| .mao | Dragon Age Origins MAO XML |
| .map | Geographical Map Format |
| .mapimail | Windows Send To Mail Recipient Format |
| .maplet | Maplet World Format |
| .maplib | Mscape Map |
| .mapsdata | Apple IOS Map Data Format |
| .mapx | Mapjects GRYD Webserver Format |
| .maq | Microsoft Access Query Shortcut Format |
| .mar | Microsoft Access Report Shortcut Format |
| .marc | MAchine-Readable Cataloging (MARC) Document |
| .markdn | Markdown Markup Language Document Format |
| .markdown | Markdown Markup Language Format |
| .mars | Adobe Mars Format |
| .marshal | Marshal Editor Data Migration Model Format |
| .mart | Martview Ebook Format |
| .mas | Microsoft Access Stored Procedures Format |
| .mash | Java |
| .mask | SpeedGrade Color Mask Format |
| .masseffectprofile | Mass Effect User Profile |
| .masseffectsave | Mass Effect Saved Game |
| .master | ASP Master Page Format |
| .mat | Microsoft Access Table Shortcut Format |
| .match-rdb | RDB |
| .material | Rigs Of Rods Texture Reference Format |
| .math | AnalyticMath |
| .matlab | Matlab Script |
| .mato | Atomic Combat Saved Game Format |
| .matproj | Dragon Age Origins Material |
| .mau | Media Attachment Unit Format |
| .maud | Amiga MAUD Sound |
| .mav | Microsoft Access View Format |
| .maw | Microsoft Access Data Access Page Format |
| .max | 3D Studio Max Scene Format |
| .maxc | 3D Studio Max Container Format |
| .maxd | PaperPort Annotation |
| .maxm | Paperport |
| .maz | Microsoft Windows Hover! Maze Format |
| .mb | Autodesk Maya Binary Scene Format |
| .mb1 | Monster Bash Game Data |
| .mb3 | Minimal Board Editor (MBE) |
| .mb4 | Model Builder Model Design |
| .mba | Martus Human Rights Bulletin System |
| .mbac | MascotCapsule Resource |
| .mbas | MikroBasic Source Code |
| .mbb | ManaBook Format |
| .mbbk | ManaBook Book Kit Format |
| .mbc | Mulberry E-mail Client Cache |
| .mbd | Multimedia Builder MP3 Authoring Format |
| .mbdb | Apple IOS Backup Manifest |
| .mbdx | Apple IOS Backup Manifest |
| .mbe | MVP Baseball 2005 Game |
| .mbf | Microsoft Money Backup Format |
| .mbfavs | Stardent AVS X Bitmap Image |
| .mbfs | Stardent AVS X Bitmap Image |
| .mbfx | AVS X Image |
| .mbg | Mailbag Assistant E-mail Archive Format |
| .mbi | MagicISO Multi-bootable Information Format |
| .mbk | DBASE IV Multiple Index File Backup |
| .mbkp | Memeo Instant Backup Backup |
| .mbl | Logger Pro Experiment Data Format |
| .mbm | EPOC Multi-bitmap Format |
| .mbox | Mail Mailbox Format |
| .mbp | Mobipocket EBook Auxiliary Format |
| .mbp1 | Kindle Touch Annotation |
| .mbr | Zune Smooth Streaming Format |
| .mbs | Opera Mailbox Format |
| .mbsa | Microsoft Baseline Security Analyzer Format |
| .mbsb | Mamut Business Software Company Database Backup |
| .mbsyncstate | Mbsync Folder Backup |
| .mbt | Blue Card Manager Merit Badge Template Format |
| .mbtemmplate | ModelBaker Custom Template Directory |
| .mbv | JVC Everio MediaBrowser Movie |
| .mbw | Easy Mail Backup Wizard Format |
| .mbx | E-mail Mailbox Format |
| .mbz | Pogoshell NES Emulator Plugin |
| .mc | Microsoft Windows Localized Message Table Resource |
| .mc1 | MedCalc Data Format |
| .mc2 | MasterCook Cookbook Recipe Text Data Format |
| .mc3 | Bridge Design Modeler 3D Match-casting Geometry Control |
| .mc4d | Cinema 4D 3D Graphic |
| .mc5 | Poser 5 Material Format |
| .mc6 | Poser 6 Material Format |
| .mc8 | Mastercam V8 |
| .mc9 | Mastercam V9 CAD Format |
| .mca | Minecraft Anvil Format |
| .mcacc | MCACC Measurement Data |
| .mcb | NEPLAN Project |
| .mcbn | Microsoft Excel 4 For Mac Chart |
| .mcc | Amiga MUI External Class Library |
| .mcd | VectorWorks Drawing Format |
| .mcdb | Adobe Premiere Pro Media Cache Database |
| .mcdx | Mathcad Prime Document Format |
| .mcf | Mathcad Font Format |
| .mcfi | Autodesk Maya Initial Fluid Cache Format |
| .mcfp | Autodesk Maya Fluid Cache Playback Format |
| .mcgame | Minecraft Backup Format |
| .mci | Media Control Interface Command Script Format |
| .mck | Macro Keys Encrypted Macro |
| .mcl | Microsoft Media Center Application Shortcut Format |
| .mclevel | Minecraft Map Format |
| .mcmac | MacGourmet MasterCook Document |
| .mcmeta | Minecraft Animation Settings Format |
| .mcml | Microsoft Windows Media Center MCML |
| .mco | MSN Messenger Wink Format |
| .mcp | MSN Content Plus Installer Format Archive |
| .mcr | Autodesk 3D Studio Max Macroscript Format |
| .mcrp | MobyExplorer Encrypted Format |
| .mcs | MathCAD Raster Picture Image Format |
| .mcsp | My Craft Studio Project Format |
| .mcsx | My Craft Studio Professional Format |
| .mct | Musicator MIDI |
| .mcusw | Nokia Mobile Phones With Symbian Firmware |
| .mcv | ManyCam Effect |
| .mcw | Microsoft Word 5 For Mac Document Format |
| .mcworld | Minecraft World Backup Format |
| .mcx | Mastercam X And X2 File Format |
| .mcxe | MedicinesComplete Data Format |
| .mcxml | Microsoft Office 2013 XML Settings |
| .mcz | Poser Compressed Material Format |
| .md | MDCD Compressed File Archive |
| .md0 | Adobe Photoshop Format Browser Metadata Cache Format |
| .md03 | Adobe Director |
| .md1 | GEAR CD Suite CD Image Format |
| .md2 | Quake 2 Model Format |
| .md2p | MessengerDiscovery |
| .md2s | MessengerDiscovery |
| .md3 | Quake 3 Model Format |
| .md4 | Quake 3 MD4 Skeletal Model Format |
| .md5 | Checksum Format |
| .md5.txt | Message Digest 5 Hash Format |
| .md5anim | Doom 3 ID Tech 4 Game Engine Model Animation Format |
| .md5camera | Doom 3 ID Tech 4 Game Engine Model Camera Format |
| .md5mesh | Doom 3 ID Tech 4 Game Engine 3D Mesh Format |
| .md8 | GarageCUBE Modul8 Project Format |
| .mda | Microsoft Access Add-in Format |
| .mdat | REW Measurement |
| .mdb | Microsoft Access Database Format |
| .mdbackup | Apple IPhone Backup Format |
| .mdbhtml | Microsoft Office Access HTML Document Format |
| .mdbx | Access Based Database |
| .mdc | Image Minolta RD175 |
| .mdd | Point Oven Deformation Data Format |
| .mddata | Apple IPhone Backup Data Format |
| .mde | Microsoft Access Compiled Database (application) Format |
| .mdes | Trimaran Machine Description |
| .mdf | Alcohol 120% Disc Image File Format |
| .mdg | Enterprise Architect |
| .mdhtml | Microsoft Access HTML |
| .mdi | Microsoft Office Document Imaging File Format |
| .mdimporter | Spotlight Importer Setting |
| .mdinfo | Apple IPhone Info Format |
| .mdk | Astra Schedule Schedule |
| .mdl | Flight Simulator 95/98 3D Model Format |
| .mdle | Motion Description Language Extended |
| .mdm | HLM Multivariate Data Matrix Format |
| .mdmp | Microsoft Windows Minidump Format |
| .mdn | Microsoft Access Blank Database Template Format |
| .mdo | Alcohol 120% Split Image |
| .mdown | Markdown Markup Language Format |
| .mdp | Microsoft Visual C++ Visual J++ MAK File (old Project Workspace) |
| .mdpf | Mac OS X Modem Preferences |
| .mdpl | MacDraw II |
| .mdr | ZX Spectrum Microdrive Emulator |
| .mdrc | MADRIX DMX Remote Configuration |
| .mdrw | MacDraw |
| .mds | Alcohol 120% Image File (media Descriptor File) Format |
| .mdt | Microsoft Access Database Template Format |
| .mdtext | Markdown Markup Language |
| .mdtxt | Markdown Markup Language |
| .mdus | MessengerDiscovery |
| .mdv | QLAY |
| .mdw | Microsoft Access Workgroup Information Format |
| .mdwn | Markdown Markup Language |
| .mdx | Media Data EXtended Image Format |
| .mdz | Microsoft Access Wizard Template Format |
| .mdzip | MagicDraw Compressed Project Format |
| .me | Readme Text Format |
| .me2headmorph | Mass Effect 2 Head Morph |
| .me2mod | Mass Effect 2 Game Modification Format |
| .mea | Mastersizer 2000 Sample Analysis |
| .meb | PRO100 Library Format |
| .mech | Pro/MECHANICA Settings |
| .MeContact | Microsoft Live Messenger |
| .med | Amiga MED Sound Format |
| .mediawiki | Mediawiki Source |
| .mef | Mamiya ZD MEF Image Format |
| .meg | MEGA Data Format |
| .mega | Megacubo Metafile |
| .mel | Maya Embedded Language |
| .mell | RedleX Mellel Document Format |
| .mellel | RedleX Mellel Document Format |
| .mem | Microsoft Visual FoxPro Mem Format |
| .memb | Pro/ENGINEER Temporary |
| .men | MenuPro Restaurant Menu Design |
| .menc | Microsoft Windows Mobile Encrypted Format |
| .menu | Apple Mac OS X SystemUIServer MenuExtra Plugin Format |
| .menudata | VMWare Cache |
| .meo | MEO Encrypted Format |
| .meq | Corel WordPerfect Macro Editor Print Queue |
| .mer | Corel WordPerfect Macro Editor Resident Area Format |
| .merlin2 | Merlin Project Format |
| .merlinlicense | Merlin License Format |
| .mes | Corel WordPerfect Macro Editor Work Space |
| .mesa | OpenGL GLUT |
| .mesh | 3D Graphic Format |
| .met | EMule Cached Information Format |
| .meta | RealPlayer Metafile |
| .meta4 | Metalink 4.0 |
| .metadata_never_index | Spotlight Never Index Format |
| .metalink | Metalink 3.0 |
| .metastock | Metastock Data |
| .metriclog | Apple IOS Diagnostic |
| .meu | DOS Shell Menu Group |
| .mew | MultiEdit Configuration |
| .mex | Corel WordPerfect Macro Editor Expound Format |
| .mex4 | Sun-4/SPARC Dynamically Linked Subroutines |
| .mexds | MATlab Dynamically Linked Subroutines |
| .mexhp3 | Matlab HP9000/series 300 Dynamically Linked Subroutines |
| .mexhp7 | Matlab HP9000/series 700 Dynamically Linked Subroutines |
| .mexn | Matlab NeXT Dynamically Linked Subroutines |
| .mexrs6 | Matlab IBM RS/6000 Dynamically Linked Subroutines |
| .mexsg | Matlab Dynamically Linked Subroutine |
| .mexw32 | MATlab Program Executable |
| .mf | Java Manifest Format |
| .mf2 | Authorware Mediator5 Multimedia |
| .mf4 | Version 4.0 Measurement Data Format |
| .mfa | Multimedia Fusion Development Format |
| .MFAlist | Ashampoo Photo Commander Slideshow List |
| .mfasl | Netscape XUL Fastload Format |
| .mfcribbon-ms | MFC Ribbon Definition XML Format |
| .mfd | Adobe Multiple Master Font Metrics Directory |
| .mfe | Character Studio Format |
| .mff | Cakewalk MIDI |
| .mfg | ProEngineer Manufacturing |
| .mfi | Windows 98 Resource Kit |
| .mfil | Blizzard Software Update Format |
| .mfj | MOBCAL Data |
| .mfk | Memsoft OS/2 Database |
| .mfl | Mozilla Firefox XUL Fastload Format |
| .mfm | VTeX Multiple Master Font Metrics |
| .mfo | Mediaface Online CD Label Software Project Format |
| .mfp | MediaFACE CD Label Software Format |
| .mfps | Scientific Calculator Plus Script |
| .mfr | Autodesk Moldflow Result |
| .mfs | MetFS Encrypted FUSE Based Formatsystem Format |
| .mft | Mediaface Project Template Format |
| .mfu | Backdoor.Win32.Agent.mfu Virus Format |
| .mfv | MobileFrame Device Pack Format |
| .mfw | Motorola MSS Box Firmware Format |
| .mfx | Multimedia Fusion Extension Format |
| .mg | EarAche Audio |
| .mg1 | MusiGenesis Project |
| .mg2 | Band-in-a-Box Song |
| .mg4 | Band-in-a-Box Song |
| .mg9 | Band-in-a-Box Song |
| .mga | Manga Comics Document Format |
| .mgb | Paragon5 Gameboy Tracker Audio |
| .mgc | MGCSoft Equation Illustrator Data Format |
| .mgcb | MGCSoft Equation Illustrator Project Format |
| .mgd | Master Grade Gradebook |
| .mgdatabase | MacGourmet Deluxe Database Format |
| .mge | MGE Data Server Project |
| .mgf | ASCII-based 3D Rendering Materials And Geometry Format |
| .mgk | ImageMagick Settings Format |
| .mgl | Age Of Empires II Age Of Kings Game Format |
| .mglr | Magellan Routes |
| .mglt | Magellan Tracklogs |
| .mglw | Magellan Waypoint |
| .mgm | MGCSoft Equation Editor Macro File Format |
| .mgmf | MindGenius Mind Map |
| .mgmt | MindGenius 2-3 Template |
| .mgmx | MindGenius Map Format |
| .mgn | Modern Genealogy Database |
| .mgo | MacGourmet Recipe Format |
| .mgourmet | Mariner MacGourmet Document Format |
| .mgourmet3 | Mariner MacGourmet Document Format |
| .mgr | MGR Bitmap Image |
| .mgs | MGCSoft Vector Shapes Format |
| .mgspot | MacGourmet Metadata |
| .mgt | ZX Spectrum Emulator Disk Image |
| .mgtheme | MacGourmet Theme Format |
| .mgtx | MindGenius XML Template Format |
| .mgu | Band-in-a-Box MIDI |
| .mgv | Sony PSP Video Format |
| .mgx | Micrografx Designer Drawing Format |
| .mgz | Metal Gear Solid Game Archive |
| .mhd | Fallout 3 |
| .mhe | MHwinEHE Project |
| .mhk | Riven Movie Data |
| .mhp | Mailshift Internet Mail Document |
| .mhs | Xilinx Platform Studio Hardware Specification Format |
| .mht | Mime HTML (MHTML) Format |
| .mhtenx | Egis Encrypted HTM |
| .mhtm | Mime HTML (MHTML) |
| .mhtml | Mime MHTML Format |
| .mhtmlenx | Egis Encrypted MHTML |
| .mhv | Husqvarna Viking Data |
| .mi | AutoVue Graphic Plugin |
| .mi2 | Autodesk Softimage |
| .mi4 | NVidia PortalPlayer Firmware Update Format |
| .mib | MyInfo Topic Backup |
| .mic | Microsoft Image Composer Image Format |
| .mid | MIDI Audio Format |
| .midi | MIDI-sequention Sound Format |
| .mif | ImageMagick Image Format Format |
| .miff | Magick Image |
| .mig | Windows Easy Transfer Migration Data Format |
| .mih | MRtrix Image Header |
| .mii | Nintendo Wii Virtual Avatar Format |
| .mik | MapInfo MapImagery Encryption Key |
| .mil | Micro Illustrator Uncompressed Image |
| .milk | Winamp MilkDrop Plugin Configuration Format |
| .millpst | BobCAD Post Processor Data |
| .mim | Multi-Purpose Internet Mail Extensions Format |
| .mime | Multi-Purpose Internet Mail Extensions (MIME) File Format Format (RFC822) |
| .min | Minute Maker Format |
| .mindnode | MindNode Document Format |
| .mine | Minecraft Map Format |
| .minesweepersave-ms | Microsoft MineSweeper Save Format |
| .mingw32 | Mingw Compiler |
| .mini2sf | Nintendo DS Sound Information Format |
| .minincsf | NCSF Nintendo DS Audio Format |
| .minipsf | Miniature PlayStation Sound Format |
| .minipsf2 | Miniature PlayStation Sound Format |
| .miniso | DVDFab Miniso Disk Image |
| .miniusf | Nintendo 64 Song Format |
| .mint | Linux Mint Installer Format |
| .mio | MIO Multimedia Format |
| .mip | Corel PaintShop Pro Multiple Image Print Format |
| .mipr | MacImage Hybrid CD-ROM Project |
| .mir | Mini Image Ripper Disk Image Format |
| .miradi | Miradi Project |
| .mis | Mission Format |
| .miso | MacImage ISO+ Project |
| .mission | MissionMaker Project Format |
| .mit | MineEdit Inventory Template Format |
| .miv | MapImagery Vendor Profile |
| .mix | Microsoft PhotoDraw Image |
| .miz | Winamp Compressed Midi |
| .mj2 | JPEG 2000 Motion Sequence Format (ISO 15444-3) Format |
| .mj3 | Id Software Online Sale |
| .mjbooktemplate | MacJournal Book Template |
| .mjd | Adobe Acrobat MIME Encoded Job Definition Format |
| .mjdoc | MacJournal Document Format |
| .mjf | Mjuice MP3 Audio |
| .mjg | Trojan |
| .mjp | VTech MJP Video Format |
| .mjp2 | JPEG 2000 Motion Sequence Format (ISO 15444-3) |
| .mjpg | Motion JPEG Video Format |
| .mjr | Media Jukebox Registration |
| .mjz | Trojan.Win32.Agent.mjz |
| .mk | Make Format |
| .mk3d | Matroska MKV 3D Stereoscopic Video Format |
| .mk4 | Schiller Medilog ECG Raw Data Format |
| .mka | Matroska Audio Format |
| .mkb | Marmalade SDK Project |
| .mkc | MagicKey Currency Exchange Rate |
| .mkd | Markdown Markup Language |
| .mkdn | Markdown Markup Language |
| .mke | Microsoft Windows SDK Make |
| .mkext | Mac OS X Mach Kernel Extension Memory Cache |
| .mkey | CompeGPS Land Registration Key |
| .mkeyb | CompeGPS Land Registration Key |
| .mkh | WinMark Pro Mark |
| .mkII | Mark2 SoundSystem Audio |
| .mkj | MKJamz Audio |
| .mkp | Cinestar Remote Control Configuration |
| .mkr | Train Simulator Marker |
| .mks | Matroska Subtitles Stream |
| .mkt | Visual FoxPro Configuration |
| .mkv | Matroska Video-audio Multimedia Format |
| .mkv3D | Matroska 3D Video Format |
| .mky | MagicKey Configuration |
| .mkz | PokerOffice Database Backup |
| .ml | ML Language Source Code Format |
| .ml2 | Tripos MOL2 Molecule |
| .ml20 | Mercury Messenger For Mac Video |
| .ml3 | Milestones Project |
| .ml4 | Milestones 4 Schedule |
| .ml5 | Milestones Project |
| .ml9 | Milestones Professional 2004U Schedule |
| .mla | WorshipCenter Pro Document |
| .mlb | Microsoft Windows Mobile Media Library Format |
| .mlc | Microsoft Windows Language Interface Pack Format |
| .mld | I-Melody Format For I-Mode |
| .mle | MAirList Event List |
| .mlf | Package Download Profile |
| .mlg | IBM Communications Server Message |
| .mli | F# Source Code |
| .mlib | Model Library |
| .mlk | Sierra MasterCook Look Format |
| .mll | AutoDesk Maya Plug-in Format |
| .mlm | Novell GroupWise Saved Email Message |
| .mln | Alchemy Source |
| .mlocate | Gnome Desktop |
| .mlp | Meridian Lossless Packing Audio Format |
| .mlr | Mollier Sketcher |
| .mls | Miles Sound Tools Compressed DLS Format |
| .mlsxml | Skype XML |
| .mlt | Forecast Pro Multivariate Forecast |
| .mlv | LabVIEW Mathscript |
| .mlw | MainLog Data |
| .mlx | Starcraft Saved Game |
| .mly | OCaml Ocamlyacc Input |
| .mm | Apple Xcode Core Objective-C Program Source Code Format |
| .mm1 | ActiveXperts MMS Toolkit Settings |
| .mm3 | Mortgage Minder Saved Mortgage Configuration |
| .mm4 | Microsoft Windows Word Processing Format |
| .mm6 | Might And Magic 6 Saved Game Format |
| .mm7 | Might And Magic 7 Saved Game Format |
| .mm8 | MusicMaker V8 Audio Format |
| .mma | Master Album Maker Album Format |
| .mmap | MindManager Map Format |
| .mmas | MindManager Theme |
| .mmat | MindManager Template Format |
| .mmb | MultiMedia Builder |
| .mmc | Microsoft Office XP Media Content Format |
| .mmch | CodeWarrior Compiled Hdr |
| .mmcollection | Microsoft Outlook Mail Manager Plug-in Collection Format |
| .mmd | Mangodata Multi-user Database |
| .mmdc | MediaMonkey Mobile Device Settings Format |
| .mmdf | Multi-channel Memorandum Distribution Facility Mailbox Format |
| .mmdl | SAPPHIRE Structure Model |
| .mmdr | Adobe Director |
| .mme | Multipurpose Internet Mail Extensions Format |
| .mmf | Microsoft Mail Message Format |
| .mmg | MKVToolNix Muxing Settings |
| .mmh | Dragon Age Model Mesh Heirarchy |
| .mmip | MediaMonkey Installation Format |
| .mmjs | Adobe JavaScript Document |
| .mmk | MACSIMUS Define |
| .mml | Adobe FrameMaker Format |
| .mmm | MultiMedia Movie Format (RIFF RMMP) |
| .mmn | Memory-Map Navigator Overlay Object |
| .mmo | RapidFile Memo Document Format |
| .mmp | MixMeister Studio Playlist Format |
| .mmpa | MoreMotion Application Studio Page |
| .mmpf | CodeWarrior Preference |
| .mmpr | CodeWarrior Project |
| .mmpz | Linux MultiMedia Studio Project |
| .mmrc | MADRIX MIDI Remote Configuration |
| .mms | Miles Sound Tools |
| .mmsw | Movie Magic Screenwriter Document |
| .mmt | CoCo Systems VisiMap |
| .mmu | MyPM Merge Data Format |
| .mmv | MicroMV Movie Format |
| .mmw | AceMoney Financial Data Format |
| .mmx | Command And Conquer Game |
| .mmz | MusicMatch Theme |
| .mn1 | Microsoft Money Version 1 Data |
| .mn2 | Descent 2 Mission |
| .mn3 | Descent 3 Mission |
| .mn4 | Microsoft Money 95 Data |
| .mn5 | Microsoft Money 97 Data |
| .mn6 | Microsoft Money 98 Data |
| .mn7 | Microsoft Money 99 Data |
| .mn8 | Microsoft Money 2000 Data |
| .mn9 | Microsoft Money 2001 Data |
| .mnb | MuPAD |
| .mnc | AutoCAD Compiled Menu Format |
| .mnd | AutoCAD Menu Compiler |
| .mne | Microsoft Money |
| .mnf | ADAMS/Flex |
| .mng | Multiple Network Graphics |
| .mnh | Master Navigator Header Format |
| .mni | Star Trek Elite Force 2 Game |
| .mnit | FlashPeak SlimBrowser |
| .mnk | My Notes Keeper Notebook Format |
| .mnl | Autodesk AutoCAD Menu LISP Format |
| .mnm | Autodesk 3D Studio Max Character Studio Marker Name Format |
| .mno | Macromedia Design Note |
| .mnp | Ultrasoft Money |
| .mnr | Autodesk AutoCAD Compiled Menu Format |
| .mns | AutoCAD Interface Settings Format |
| .mnt | Visual FoxPro Additional Menu Description Format |
| .mnu | Autodesk AutoCAD Menu Format |
| .mnv | Sony PlayStation Movie Format |
| .mnx | Visual FoxPro Main (DBF) Menu Description Format |
| .mny | Microsoft Money Data Format |
| .mo | GNU Gettext Machine Object Format |
| .mo3 | MO3 MOD Audio Format |
| .mo? | Standard Mail Archive |
| .mob | MOBTV Video Format |
| .mobi | Mobipocket EBook Format |
| .mobileconfig | Apple IPhone Mobile Configuration Profile |
| .mobileprovision | IOS Mobile Device Provisioning Profile Format |
| .moc | MOCHA Java Script |
| .mocha | Adobe Mocha For Adobe After Effects |
| .mod | Hard Disk Camera Movie MPEG-2 Program Stream Format |
| .modd | Sony Video Analysis Format |
| .mode | Coda For Mac Plugin Format |
| .mode1v3 | Xcode Project Settings |
| .mode2v3 | Xcode Project Related |
| .model | CATIA V4 Model Format |
| .modelproj | Microsoft Visual Studio Modelling Project |
| .module | Drupal Module Format |
| .modus | Adobe Mocha For Adobe After Effects Modus |
| .mof | Systems Management Server Managed Object Format |
| .moff | Sony AVCHD Index Format |
| .mog | Football Mogul |
| .mogg | Multitrack Digital Audio Format |
| .moho | Anime Studio Animation Project Format |
| .moi | JVC Everio Digital Audio Format |
| .mojito | Limewire Kademlia |
| .mokey | Adobe Mocha For Adobe After Effects Mokey |
| .mol | MDL Molfile Molecule Format |
| .mol2 | Portable Representation Of A SYBYL Molecule |
| .mologiq | HTC EVO 3D |
| .mom | Managed Object Model |
| .momma | Offspring Fling Replay Format |
| .mon | Firefox Monday Bookmark Backup |
| .monet | Adobe Mocha For Adobe After Effects Monet |
| .money | Money Data Format |
| .moneywell | MoneyWell Financial Data Format |
| .monitorPanel | Apple Mac OS X Display Panel Extension |
| .mono | Bi-level Bitmap |
| .montage | Montage Screenplay Format |
| .monte | CRiSP Harvest |
| .moo | Apple QuickTime Movie Clip |
| .mood | Amarok Moodbar Data |
| .moov | Apple QuickTime Movie Format |
| .mop | MOPAC Input Format |
| .mopint | Mopac Internal Chemical Modeller Input |
| .mopout | MOPAC Chemical Output |
| .mopp | Havok Engine |
| .mor | Corel Shared Writing Tools |
| .morg | Morg |
| .morse | Ringtone Morse Code |
| .mos | Mamiya Digital Camera RAW Image Format |
| .mosaic | MacOSaiX Mosaic Format |
| .moss | Netscape Navigator For Mac HTML |
| .mot | LightWave Motion Format |
| .motn | Apple Motion Motion |
| .motor | Adobe Mocha For Adobe After Effects Motor |
| .mou | MOU Compressed Format |
| .mov | Apple QuickTime Digital Movie Format |
| .movie | Apple QuickTime Movie Format |
| .mox | ExtendSim Model Format |
| .moxel | Adobe Mocha For Adobe After Effects Moxel |
| .moz | Netscape Temporary Cache Format |
| .moz-backup | Mozilla Backup |
| .moz-delete | Mozilla Firefox Update |
| .moz-upgrade | Mozilla Firefox Upgrade |
| .mozeml | Mozilla Thunderbird Mail Message |
| .mp | Autodesk Maya Personal Learning Edition Format |
| .mp+ | MPEG Plus Audio |
| .mp1 | MPEG Audio Stream, Layer I Format |
| .mp10 | NI Multisim V10 Project Format |
| .mp11 | NI Multisim V11 Project Format |
| .mp2 | Sound File (MPEG-1 Layer II Audio Stream) |
| .mp21 | MPEG-21 Multimedia Format |
| .mp2a | Sound File (MPEG-1 Layer II Audio Stream) |
| .mp2m | Max Payne 2 Mod Format |
| .mp2s | Max Payne 2 Saved Game Format |
| .mp2v | MPEG Video Format |
| .mp3 | Compressed Audio And Music File, Mp3 Songs Or Ringtones |
| .mp3a | Renamed MP3 |
| .mp3g | WinCDG Pro MP3+G Karaoke |
| .mp4 | MPEG-4 Video File Format |
| .mp4.infovid | Parrot AR Drone And Gyro Flyer Video |
| .mp4a | MPEG-4 MP4A Codec Audio |
| .mp4b | MPEG-4 Audio Layer Bookmarkable |
| .mp4v | MPEG-4 Video Format |
| .mp5 | Maple Windows DOS |
| .mp7 | NI Multisim V7 Project Format |
| .mp8 | NI Multisim V8 Project |
| .mp9 | NI Multisim V9 Project Format |
| .mp? | LoseThos Compiler Map |
| .mpa | MPEG Audio Format |
| .mpb | MyPhoneExplorer Backup Format |
| .mpc | MusePack Audio Format |
| .mpcpl | Media Player Classics Playlist Format |
| .mpd | Microsoft Project Database Format |
| .mpdb | Windows Media Player Database |
| .mpdconf | Music Player Daemon Settings Format |
| .mpdp | MixPad Project Format |
| .mpds | MADRIX Plexus Settings |
| .mpe | MPEG Movie (Motion Pictures Experts Group) |
| .mpeg | MPEG Movie |
| .mpeg1 | Multiplexed MPEG-1/2 Format |
| .mpeg2 | Multiplexed MPEG-1/2 |
| .mpeg4 | MPEG-4 Video Format |
| .mpega | MPEG Sound |
| .mpf | Microsoft Design Gallery Format |
| .mpg | MPEG 1 Video File Format |
| .mpg2 | MPEG-2 Video Format |
| .mpg3 | MP3 Audio File For Mac |
| .mpg4 | MPEG-4 Video |
| .mpga | Mpeg-1 Layer3 Audio Stream |
| .mpgindex | Adobe MPEG Index Format |
| .mpgv | MPEG-2 Video |
| .mph | Microsoft Publisher |
| .mpi | InstallJammer Project Format |
| .mpj | MINITAB Spreadsheet Project Format |
| .mpk | Painkiller Overdose Game Map Format |
| .mpkg | Meta Package Format |
| .mpkt | MOPEKS Trial |
| .mpl | AVCHD Playlist Format |
| .mplf | CodeWarrior Library |
| .mpls | Blu-ray Movie Playlist Information Format |
| .mpm | Corel WordPerfect MathPlan Macro Format |
| .mpnt | MacPaint Image Format |
| .mpo | CIPA Multi-Picture Format |
| .mpp | Microsoft Project Plan Format |
| .mppx | Microsoft Project Project |
| .mppz | MagicPlot Project Format |
| .mpp_ | Microsoft Project For Mac Plan |
| .mpq | Blizzard Entertainment Archive |
| .mpqe | Blizzard Encrypted Game Data |
| .mpr | Visual FoxPro Generated Menu Program |
| .mprj | Maschine Project |
| .mps | Microsoft Pocket Streets Map Format |
| .mpsub | Subtitle Format |
| .mpsy | CodeWarrior Debug Symb |
| .mps_ | MPW Shell |
| .mpt | Microsoft Project Template Tile |
| .mpu | MPEG Layer 3 Audio Format |
| .mpv | MPEG 1 Video Format |
| .mpv2 | MPEG II Video Format |
| .mpvf | CompeGPS Land Fast Vector Map |
| .mpw | Microsoft Project Workspace Format |
| .mpwd | MacWrite Pro |
| .mpwr | MacWrite Pro |
| .mpx | Microsoft Project Export Format |
| .mpz | Miradi Project Format |
| .mpzip | Multisim Pack Format |
| .mp_ | Mobile Phone Sound Format |
| .mq4 | MetaTrader Custom Indicator Format |
| .mqh | MetaTrader Trading Terminal |
| .mql | MetaTrader Indicator |
| .mqo | Metasequoia 3D Image Format |
| .mqt | MetaQuotes Language 4 MQL4 Template |
| .mqv | Sony Movie Player File Format |
| .mraw | Photron Camera RAW Image |
| .mrb | C++ Multiple Resolution Bitmap Graphic Format |
| .mrc | MIRC Script Format |
| .mrd | MathRevolt Infinity Document |
| .mrec | MADRIX Record |
| .mrf | Macintosh Font |
| .mrg | MySQL Reference Format |
| .mrimg | Macrium Reflect Disk Image Backup |
| .mrk | DPOF Digital Print Order Format Auto Print Order Format |
| .mrl | MRLR Multimedia Retrival Markup Language |
| .mrm | Gothic 2 |
| .mrml | 3D Slicer Scene Description Format |
| .mro | SharpEye Music Reader |
| .mrp | Infinity Solution Plot |
| .mrs | Corel WordPerfect Macro Resource Format |
| .mrt | Microsoft Visio 2010 Installation Archive Format |
| .mrv | MarvinSketch |
| .mrw | Minolta Dimage RAW Image Format |
| .mrxs | MIRAX Virtual Slide Format |
| .ms | 3D Studio Max Script Source Code |
| .ms-tnef | Microsoft Transport Neutral Encapsulation Format |
| .ms1 | VirtualBus Map Format |
| .ms10 | NI Multisim V10 Circuit Design Format |
| .ms11 | NI Multisim V11 Circuit Design Format |
| .ms2 | SEQUEST Ms2 |
| .ms3d | MilkShape 3D Model Format |
| .ms7 | NI Multisim V7 Circuit Design Format |
| .ms8 | NI Multisim V8 Circuit Design Format |
| .ms9 | NI Multisim V9 Circuit Design Format |
| .msa | Magic Shadow Archiver Atari Disk Image |
| .msb | The Bat! Format |
| .msc | Microsoft Management Console Control Format |
| .mscg | Microsoft Clip Art Gallery For Mac |
| .mscr | Rename Master Scrip |
| .msct | MOPEKS Script |
| .mscx | MuseScore Music Score Format |
| .mscx, | MuseScore Music Score Backup |
| .mscz | MuseScore Compressed Music Score Format |
| .mscz, | MuseScore Music Score Backup |
| .msd | Map Service Definition Format |
| .msdev | Microsoft Visual C+ Make |
| .msdl | Manchester Scene Description Language |
| .msdm | Microsoft Windows |
| .msdvd | Microsoft Windows DVD Maker Format |
| .mse | 3D Studio Max Encrypted MAXScript Format |
| .mse-installer | Magic Set Editor Installer |
| .msf | Mozilla Thunderbird Mail Summary Format |
| .msg | Saved Email Message |
| .msgr | Microsoft Graph 5 |
| .msh | MASH Microsoft Agent Script Helper Format |
| .msha | Microsoft Help Library Help Manifest Format |
| .mshc | Microsoft Help Container Format |
| .mshdb | Ministry Scheduler Pro Database |
| .mshi | Microsoft Help Index Format |
| .mshxml | Microsoft XML Typedata |
| .msi | Microsoft Windows Installer Installation Package |
| .msie | Microsoft Internet Explorer For Mac HTML |
| .msif | MyLabel Designer Deluxe Label Format |
| .msil | Microsoft Intermediate Language |
| .msj | MicroSurvey CAD Temporary |
| .msk | Corel PaintShop Photo Pro Mask Image Format |
| .mskin | Maxthon Skin |
| .mskn | MediaMonkey Skin Format |
| .msl | Miranda IM Smiley Definitions |
| .mslz | Archive |
| .msm | Windows Installer Merge Module |
| .msmessagestore | Windows Mail Message Information Database |
| .msn | Microsoft Windows Network Related Format |
| .mso | Microsoft Organization Chart Chart Format |
| .msof | Microsoft Office For Mac |
| .msp | Windows Installer Patch Format |
| .mspx | Microsoft XML-based Web Page |
| .msrcincident | Microsoft Windows Remote Assistance Request Format |
| .mss | Miles Sound System DLS 1 Sound Format |
| .msstyle | Windows XP Unsigned Style |
| .msstyles | Microsoft Windows Resources Themes Luna Format |
| .mst | Windows Installer Transform Script Format |
| .mstat | SAM Domain Output |
| .mstt | Prosa Minispecification |
| .msu | Microsoft Update Standalone Package Format |
| .msv | Sony Memory Stick Compressed Voice Files |
| .msvc | Microsoft Visual C++ Compiler Makefile |
| .msw | Microsoft Word 5 Document Format |
| .mswd | Microsoft Word For Mac Document |
| .mswk | Microsoft Works For Mac |
| .mswmm | Microsoft Windows Movie Maker Project Format |
| .msx | Age Of Empires II Saved Game |
| .msym | ArchiCAD For MAC Geometric Description Language |
| .msz | MediaMonkey Skin |
| .ms_ | Microsoft Windows Winhelp Compressed |
| .mt2 | MadTracker 2 Module Format |
| .mt9 | MT9 Audio Format |
| .mta | Samsung AllShare Metadata Format |
| .mtb | MediaTracker Database Backup |
| .mtc | MediaTracker Database |
| .mtd | Musicnotes Digital Music Sheet Format |
| .mtdd | MEDITECH Document Definition |
| .mte | MadTracker Envelope Gile |
| .mtf | Motorola Theme Format |
| .mtg | Making The Grade |
| .mth | Derive Math Format |
| .mthd | MOPEKS Method |
| .mti | MadTracker 2 Instrument Format |
| .mtiff | Multi-page Tiff |
| .mtk | MPU-401 Trakker |
| .mtkey | ProDAD Heroglyph License |
| .mtkt | MTK GPS Receiver Data |
| .mtl | OBJ Material Format |
| .mtm | MultiTracker Music Module (MOD) Format |
| .mtml | Meaningful Text Markup Language |
| .mtn | Match! Database |
| .mto | FastCAM MTO Data |
| .mtp | Minitab Portable Worksheet Format |
| .mtr | RealFight Radio Control |
| .mtra | MascotCapsule Resource |
| .mts | AVCHD MPEG-2 Transport Stream Format |
| .mts1 | MPEG-2 Transport Stream |
| .mtt | Microsoft Messenger Saved Contact Format Format |
| .mtv | MTV Video Format |
| .mtw | Minitab Data Format |
| .mtx | Microsoft Visual Studio Manual Test Text Format |
| .mtxt | MOPEKS Problem |
| .mtz | Compressed MetaStream Scene Format |
| .mt_ | Encore Compressed |
| .mu | Corel Quattro Pro For DOS Menu Definition Format |
| .mu3 | Myriad Packed Musical Score |
| .muc | Music Collector Collection Data |
| .mud | Textease Multi User Database |
| .muf | Alpha Five Access Control Format |
| .mug | Hanes T-ShirtMaker Document |
| .mui | MultiLanguage Windows Resource Format |
| .muimanifest | Microsoft Windows Multilingual User Interface |
| .mui_cccd5ae0 | Hid User Library |
| .mul | Ultima Online Game |
| .mulib | Adobe Muse Exported Library |
| .mult | SAM Alignment Output |
| .mum | Windows Vista Update Package Format |
| .mup | Music Publisher Data Format |
| .mus | Finale Music File Format |
| .mus10 | Audio |
| .musa | Aleph One Music Format |
| .muse | Adobe Muse Project Format |
| .musx | Min‐U‐Script Xpress Transcript Data |
| .mut | Integrative Genomics Viewer Mutations List |
| .mux | TrackMania Music Format |
| .muz | MUZ Audio Format |
| .mv | IRIX Command Compressed Movie Format |
| .mv1 | Video |
| .mv4 | Apple QuickTime Video |
| .mv85 | Adobe Director For Mac Movie |
| .mv93 | Adobe Director For Mac Movie |
| .mv95 | Adobe Director For Mac Movie |
| .mva | Microsoft Setup Archive |
| .mvb | Multimedia Viewer Book Format |
| .mvc | Sony Digital Mavica Photo Image Format |
| .mvd | Movie Edit Pro Video Format |
| .mvdx | MindView MindMap Archive |
| .mve | Interplay Video Format |
| .mvex | Muvee AutoProducer Unicode Document Format |
| .mvf | AutoFlix Stop Frame |
| .mvg | ImageMagick Proprietary Vector Graphics Format |
| .mvi | Autodesk AutoCAD Movie Command Format |
| .mvl | Medison 3D Volume Data |
| .mvm | MAGIX PhotoStory On DVD Slideshow |
| .mvp | Movie Edit Pro Video Project Format |
| .mvr | IBM HotMedia Multimedia Format |
| .mvs | MusicMatch Jukebox Visualization Format |
| .mvt | Ultimate Wish Lists Template |
| .mvv | AVS Media Player MPEG Video |
| .mvw | Saber LAN Log |
| .mvx | Multimedia Fusion Movement Extension Format |
| .mvy | MAGIX Video Easy Project Format |
| .mv_ | Magix Movie Edit Pro Movie Backup Format |
| .mw | Maple Worksheet Format |
| .mw2 | MicroWorlds Logo Activity |
| .mw2d | Apple MacWrite |
| .mw2s | MacWrite II Model |
| .mw4 | MechWarrior Game Structure File Archive |
| .mwand | Apple GarageBand MagicMentor Tepmplate Format |
| .mwav | Extended WAV |
| .mwb | MySQL Workbench Database Models |
| .mwc | Make Project Creator Input |
| .mwd | Mariner Write Document Format |
| .mwdp | CodeWarrior Debugger |
| .mwe | OpenArchitectureWare Workflow |
| .mwf | MapGuide Format |
| .mwi | Medlin Payroll Software Invoice Layout Information |
| .mwii | MacWrite II Text Document |
| .mwk | MusicWrite Music Score |
| .mwlic | MoneyWell License Information Format |
| .mwp | Lotus Word Pro 97 Smartmaster Format |
| .mwpd | MacWrite Pro Document |
| .mwpp | MacWrite Pro Document |
| .mwpr | MacWrite Pro |
| .mws | Maple Spreadsheet Document Format |
| .mwt | MetaStock Stock Analysis Template |
| .mwx | Autodesk MapGuide Author Map Window XML Format |
| .mx | Matlab Common Matrix Routines Format |
| .mx1 | Coucoucircus.org Audio Temporary |
| .mx2 | MasterCook Recipe |
| .mx3 | Mixcraft Project Format |
| .mx4 | Mixcraft 4 Audio Format |
| .mx5 | Mixcraft 5 Audio Format |
| .mx5template | Mixcraft Audio Project Template Format |
| .mx6 | Mixcraft 6 Audio |
| .mxad | Mandelbrot Explorer All Data Format |
| .mxaddon | Maxthon Addon Format |
| .mxc | ArcView Geocoding Index For Read-write Coverages |
| .mxc2 | MAGIX Music Maker Cache |
| .mxc3 | Magix Photo Manager Thumbnail Cache |
| .mxcs | Mandelbrot Explorer Colour Scheme Format |
| .mxd | ArcGIS Map Document Format |
| .mxdic | Maxthon Dictionary Format |
| .mxdl | Maxthon Incomplete Download |
| .mxe | Corel Quattro Pro Startup Macro Format |
| .mxf | Material Exchange Format |
| .mxfd | ABBYY Form |
| .mxfr | Mandelbrot Explorer Fractal Region Format |
| .mxg | Miinoto Exchangeable Group Format |
| .mxi | Adobe Dreamweaver Extension Manager Format |
| .mxit | MXit Data |
| .mxl | Compressed MusicXML Music Notation Format |
| .mxm | MixMeister BPM Calculation Format |
| .mxmf | Mobile XMF Format |
| .mxml | Adobe Flex Interface Component Format |
| .mxn | Miinoto Exchangeable Note Format |
| .mxp | Adobe (Macromedia) Extension Package Format |
| .mxprj | Maschine 2.0 Project |
| .mxs | Maxwell Render Scene Definition Format |
| .mxsd | IBM WebSphere Message Definition |
| .mxskin | Maxthon Skin Format |
| .mxt | ArcGIS ArcMap Map Template Format |
| .mxv | MAGIX Movie Edit Pro Video Format |
| .mxz | Maximizer Data |
| .my3D | My3D Tools Exported |
| .myapp | Microsoft Visual Studio Application XML Format |
| .myb | MYOB Data |
| .mycolors | Stardock MyColors Theme Format |
| .myd | MySQL Database Data Format |
| .mydocs | Send To Format |
| .mye | MYOB |
| .myi | MySQL Database Index Format |
| .myl | MyLogo Maker Image |
| .myo | MYOB Data |
| .myob | MYOB Data |
| .myox | MYOB Data |
| .myp | Warhammer Online: Age Of Reckoning |
| .myr | Myriad Music Format |
| .mys | Vineyard Captured Video Format |
| .myv | Vivaldi Studio Score |
| .mz | Mozart Compressed |
| .mz2 | Maze-solver MZ2 |
| .mzb | MegaZeux Board |
| .mze | Maze Creator |
| .mzf | MediaZip Archive |
| .mzp | Autodesk 3D Studio Max MAXScript Zip Package |
| .mzt | MOZART Template |
| .mzv | Viewpoint Media Player ZoomView Titles |
| .mzz | Microsoft .NET Framework Installation Package Format |
| .m_p | Pro/ENGINEER Temporary |
