M4

M4 or M-4 may refer to:

In computers:
*m4 (computer language), a macro processing language
*GNU m4, the GNU version of the m4 language

In firearms and military equipment:
*M4 Carbine, an assault rifle
*M4 Sherman, the primary tank used by the Americans in World War II
*Benelli M4 Super 90, a combat shotgun
*M2/M4 Selectable Light-weight Attack Munition (SLAM), a land mine
*M4 (cipher), a variant of the Enigma machine
*M4 flame fuel thickening compound, a substance used in fire bombs and incendiary weapons
*Myasishchev M-4, a Soviet strategic bomber
*M4 SLBM, a French submarine-launched ballistic missile
*Spectre M4, a submachine gun

In science:
*Messier 4 (M4), a globular cluster in the constellation Scorpius

In transportation:
*Metroad 4 (M4), a metroad in Sydney, Australia
*M4 Western Motorway, a segment of Metroad 4 in central Sydney, Australia
*M4 motorway, a motorway in the United Kingdom that links London with South Wales
*M4 motorway, a motorway-grade section of the N4 road in the Republic of Ireland
*M-4 (Michigan highway), a former designation for the M-134 and M-10 Michigan state highways
*M4 motorway (Russia), another name for the Don Highway in Russia
*M4 motorway (Pakistan), a proposed motorway for Pakistan
*M4 Vacamatic, a semi-automatic transmission made by Chrysler

In rail:
* M4, the fourth line of Budapest Metro, Hungary
* M4 Line, part of the Bucharest Metro, Romania
* M4, a subway car; 220 were delivered to SEPTA by Adtranz in 1999-2000

In aircraft :
* Miles M.4 Merlin, a 1930s British five-seat cabin monoplane

In hardware:
*M4 screw, a metric screw

In economics:
*M4 money supply, the total amount of money in bank accounts and in circulation in the United Kingdom