M, FILE EXTENSIONS STARTING FROM LETTER - M

M
Ext.	Description	Used by
M	Mathematica Package File	Mathematica
M	MATLAB M-File	MATLAB
M2	WoW Model Object file	Blizzard Entertainment games (World of Warcraft/Warcraft series)
M2TS	MPEG 2 Transport Stream	Various media playback devices / software
M3U	M3U playlist file	Winamp, XMMS
M3U8	Unicode version of M3U playlist file (UTF-8)	Winamp, XMMS
M4A	Advanced Audio Coding
M7P	Multilizer 2007 and 2009 localization project file	Multilizer
MAI	Mail	VAX
MAK	Makefile
MAK	Project file	VB - VC ++
MAN	User guide (manual)
MAP	Color palette file
MAP	Format data	Micrografx Picture Publisher
MAP	Linker map file
MAP	Map file (usually created by compilers)
MAP	Map	Atlas MapMaker
MAP	Network map	AccView
MAP	Game map for Duke Nukem 3D
MAR	Assembly program	VAX Macro
MAR	Microsoft ARchive	MSN Explorer (possibly other Microsoft products too)
MAR	Mozilla ARchive	Mozilla Updater (used to house binary updates to products)
MAS	SmartMaster set	Freelance Graphics
MAT	Data	MATLAB
MAT	Microsoft Access Table	Microsoft Access
MAX	MAX source code file
MB	Memo field values for database	Paradox
MBK	Multiple index file backup	dBASE IV
MBX	Mailbox data	Eudora/ZERBERUS
MCC	Configuration file	Mathcad
MCD	MathCad file	MathCad
MCF	Font file	Mathcad
MCF	Photo book or photo calendar layout file	FotoInsight Designer
MCF	Multimedia Container Format (predecessor of Matroska)
MCI	MCI command script	Media Control Interface
MCL	Multi Edit macro library	Multi Edit
MCL	Cartesian manipulator for laser systems
MCP	Application script	Capsule
MCP	Printer driver	Mathcad
MCW	Text file	MacWrite II
MDL	Quake 1 Model File	id Software
MD2	Quake 2 Model File	id Software
MD3	Quake 3 Model File	id Software
MD5	Doom 3 and Quake 4 Model File	id Software
MD	Archive	mdcd10.arc
MDA	Data	Microsoft Access
MDA	Microsoft Access system database	Microsoft Access
MDB	Microsoft DataBase	Microsoft Access
MDF[disambiguation needed]	Several uses
MDL	Model	3D Design Plus or Simulink
MDL	Spreadsheet	CA-Compete!
MDM	Modem definition file	TELIX
MDMP	Mini dumpfile
MDR	Microdrive file	ZX Spectrum emulator by g.a.lunter
MDS	Midi Session	Sound Imp.
MDT	Data table	Microsoft ILink incremental linker
MDX	Multiple index file	dBASE IV
MDZ	Text description of music module	Cubic Player - Cross-View
ME	MultiEdit configuration	MultiEdit
ME	Text file READ.ME
MEB	Macro Editor bottom overflow file	WordPerfect Library
MEC	MECCA source	Maximus
MED	Macro Editor delete save	WordPerfect Library
MED	Music format	MED/OctaMED
MEM	Macro Editor macro	WordPerfect Library
MEM	Memory variable save file	dBASE IV - FoxPro - Clipper
MEM	Memos datafile	Clarion
MEM	Mnemosyne database	Mnemosyne; other spaced repetition software
MEQ	Macro Editor print queue file	WordPerfect Library
MER	Macro Editor resident area (vakioalue)	WordPerfect Library
MES	Macro Editor work space file	WordPerfect Library
MES	Message
MET	Document	Omnipage Pro
MET	Macro Editor top overflow file	WordPerfect Library
MET	OS/2 graphics metafile	PICVIEW.EXE
MEU	Menu group	DOS Shell
MEX	Macro Editor expound file	WordPerfect Library
MEX	MEX file (executable command)	Matlab
MF	Metafont file	TeX
MFA	Source code file	Multimedia Fusion 2 / The Games Factory 2
MFF	MIDI	Cakewalk, MTPro 4
MFM	Music format	DMP
MGF	Font	Micrografx
MGF	Materials and Geometry Format
MGX	Designer 4.1 Drawing	Designer 4.1
MHT	Web Archive Single File
MIB	Snmp MIB file
MID	Standard MIDI file	music synthetizers, Winamp
MIDI	See MID
MIFF	Magick Image File Format
MII	Datafile	MicroStat-II
MIME	Message in MIME format (RFC822)
MIO	MyInfo topic	Milenix MyInfo
MIS	Mission, used by many games
MIX	Object file	Power C
MK	Makefile
MK	Makefile
MK	Usually makefile
MKE	Makefile	Microsoft Windows SDK
MKG	Makefile
MKI	Graphics format (Japan MKI)
MKI	Japanese graphics MAKIchan format	MagView 0.5
MKS	Data	TACT
MKV	Matroska Multimedia Container	Media Player Classic, Windows Media Player, Matroska Splitter
ML3	Project	Milestones 3.x
MLB	Macro library file	RT-11, Symphony
MLI	3DS Materials Libraries	3D Studio
MLRAW	Data	Moonlight Creator RAW format 3D object
MLV	LabVIEW MathScript
MM	Text file	MultiMate Advantage II, FreeMind mind map file (XML)
MMF	Mail message file	Microsoft Mail
MMM	Multimedia movie file, RIFF RMMP format	MacroMind Director 3.x
MMO	Memo writer file	RapidFile
MMP	Output video format from Bravado board
MN	MuPAD Pro Notebook	Workspace file of MuPAD (integrated in Matlab)
MND	Menu source	AutoCAD Menu Compiler
MNG	Map	DeLorme Map'n'Go
MNT	Additional (FPT) menu description file	FoxPro
MNT	Menu memo	FoxPro
MNU	Advanced macro file	HP NewWave
MNU	Menu	AutoCAD Menu Compiler - Norton Commander - Signature
MNU	Microsoft Mouse menu (for DOS apps)
MNX	Compiled menu file	AutoCAD
MNX	Main (DBF) menu description file	FoxPro
MNY	Account book	Microsoft Money
MO?	Packed mail	FTN software
MOB	Device definition file	PEN Windows
MOBI	eBook	Mobipocket
MOD	Modula language source
MOD	MODULA-2 source code file	Clarion Modula-2
MOD	Module—used by Windows for DLL which implement DOS support	Win
MOD	Music format (Amiga module)	DMP - ST - MDP - VP
MOL	MOD4WIN PlayList	Mod4Win
MOL	MDL Molfile	RasMol
MOL2	Tripos’ Sybyl MOL2 Format	SYBYL, RasMol
MON	SYSGEN monitor build procedure	RT-11
MON	Monitor description	ReadMail
MOP	MOPAC input file	MOPAC, RasMol
MOV	Animation format (Mac)	QuickTime
MOV	Movie file	AutoCAD AutoFlix
MP2	Mpeg audio file	Winamp, xing
MP3	MPEG audio stream, layer 3	AWAVE, CoolEdit(+PlugIn), Winamp, many others
MP4	multimedia container format, MPEG 4 Part 14	Winamp
MPA	MPEG audio stream, layer 1,2,3	AWAVE
MPC	Calendar file	Microsoft Project
MPC	Musepack audio
MPEG	multimedia containter format, video, audio	MPEG Player, Winamp
MPG	see MPEG
MPKG	Multipackage installer script	Mac OS X
MPL	MediaRack Midi Playlist	MediaRack
MPM	MathPlan macro	WordPerfect Library
MPP	Project file	Microsoft Project
MPPZ	MagicPlot project file	MagicPlot
MPQ	Mo'PaQ Archive	Blizzard games
MPR	Generated executable menu file	FoxPro
MPR	Multilizer 5.x and 6.x localization project file	Multilizer
MPR	Command & Conquer: Red Alert 2 map file	Red Alert 2
MPT	Bitmap graphics (Multipage TIFF)
MPV	View file	Microsoft Project
MPX	Compiled executable menu file	FoxPro
MPX	Video format
MPZ	Miradi Project Zipfile	Miradi
MRB	Multiple Resolution Bitmap graphics file	Microsoft C/C++
MRC	mIRC file	mIRC
MRK	Windows User Benchmark	Win95
MRS	Macro Resource file	WordPerfect for Win
MS	Microsoft antivirus report	MSAV
MSC	Microsoft C makefile
MSC	management saved console[2]	Microsoft; Microsoft MMC[3]
MSI	Windows Installer Package	Windows Operating Systems
MSDL	Manchester Scene Description Language
MSG	Message base (e.g. HMB)
MSG	Message text file (ASCII)	Microsoft Outlook
MSG	ZVoice digitized voice file
MSE	Set file	Magic Set Editor
MSO	Microsoft Word OLE Web Page Storage Stream	Microsoft Office
MSO	Microsoft Outlook metadata for a Microsoft Word 2000 email attachment.[4]	Microsoft Outlook
MSP	Bitmap graphics file	Microsoft Paint
MSP	Graphics format	Microsoft Paint
MSPRODUCER	Media Project	Microsoft Producer (for Microsoft PowerPoint XP/2003) Project
MSQM	data	Microsoft Message Queuing
MSN	Project	National Instruments for NI MultiSim-Electronic Circuit simulator
MSS	Manuscript text file	Perfect Writer - Scribble - MINCE - Jove
MST	Document	MS Test
MST	Minispecification file	Prosa
MST	Setup script file	Microsoft Windows SDK
MSW	Text file	Microsoft Word
MSX	CP/M archive	MSX
MTH	Math file	Derive
MTL	Wavefront
MTM	Music format	MultiTracker
MTS	Master Track Pro Files	MTPro 4
MTS	data	F1 2001, F1 2002 and F1 Challenge 1999 - 2002 car physics (All from the EA Sports F1 Series)
MTV	MTV Ray Tracer graphic file
MTW	Datafile	Minitab
MU	Quattro pro for DOS Menu definition file	Quattro Pro
MUS	Finale music document.	Finale
MUS	Music format (MIDI in Doom)
MUS	Sound file	MusicTime
MUZ	Hover Game MIDI File	Windows' Hover! Game[5]
MVF	Stop frame file	AutoCAD AutoFlix
MVI	Movie command file	AutoCAD AutoFlix
MVO	Data	Mad Virgin 3D object
MVW	Log file	Saber LAN
MWF	Animation	ProMotion
MWS	MWave DSP synths instrument	AWAVE
MXF	Material exchange format (RFC 4539, SMPTE 377M)
MXL	PackRat 5.0 support DLLs	PackRat 5.0
MXM	Material	Maxwell Render
MXP	Adobe Extension File	Adobe Dreamweaver and Adobe Flash
MXP	3ds Max Configuration File	3ds Max
MXP	MasterCook exported recipe
MXT	Data	Microsoft C
MYP	Presentation	MM Make Your Point
MZ	Binary-format Map	MazeEdit
MZE	Text-format Map	MazeEdit
MZG	Binary-format Map Collection	MazeEdit
MZX	Binary-format Encrypted Map	MazeEdit