L4 or L-4 may refer to :

Transportation

  • L 4, an Imperial German Navy Zeppelin airship active during the First World War
  • SP&S Class L-4, an 1884 steam locomotives class
  • USS L-4 (SS-43), a 1915 United States Navy L-class submarine
  • HMS L4, a 1918 British L class submarine
  • Lawson L-4, a 1924 American unflown biplane airliner
  • Piper Cub (U.S. military designation: L-4), an aircraft
  • Inline-four engine (L4), a type of inline internal combustion four cylinder engine
  • Liberty L-4, a World War I four-cylinder, water-cooled, inline, aero-engine
  • Lynx Aviation (IATA code)
  • L4 (New York City bus), a temporary bus route in New York City
  • L4, an S-Bahn line of the Léman Express in Switzerland and France
  • Parramatta Light Rail, also known as the L4, a light rail service in Parramatta, Sydney, Australia
  • Chaika L-4, a Russian twin-engined amphibious aircraft
  • Soviet submarine L-4

Science and technology

  • L4 microkernel family, a family of operating system kernels
  • L4, the transport layer in the OSI model of computer communications
  • L4, the fourth Lagrangian point in an astronomical orbital configuration
  • L<sup>4</sup>, an L<sup>p</sup> space for p=4 (sometimes called Lebesgue spaces)
  • L-4, the fourth iteration of L-carrier, high capacity frequency division multiplex over coaxial cable used by the Bell System
  • L4 paper; see Paper size

Biology

  • Haplogroup L4 (mtDNA), a human mitochondrial DNA haplogroup
  • Ribosomal protein L4, a human gene
  • L4, a lumbar vertebra of the vertebral column, in human anatomy
  • The fourth and last larval stage in the Caenorhabditis elegans worm development

Other uses

  • L4, a modern version of the Bren light machine gun in the British Army
  • ISO/IEC 8859-4 (Latin-4), an 8-bit character encoding

See also

  • L04 (disambiguation)
  • Level 4 (disambiguation)
  • 4L (disambiguation)
  • LIV (disambiguation)