Simplex may refer to:

Biology

  • List of species named simplex, a common species name
  • Herpes simplex, a viral disease caused by Herpes simplex viruses

Companies and branded products

  • Simplex (bicycle), a French bicycle derailleur brand
  • Simplex Manufacturing Corporation, an American manufacturer of motorcycles in Louisiana from 1935 to 1975
  • American Simplex, an American automobile made in Mishawaka, Indiana, US
  • Simplex Automobile Company, a defunct luxury car manufacturer from 1907 to 1921
  • Crane-Simplex, a defunct luxury car manufacturer in New York, US at the start of the 20th century
  • Sheffield-Simplex, a British vehicle manufacturer operating 1907–1920
  • Bergmann Simplex, an early 20th-century, German-made handgun
  • Mercedes Simplex, an automobile model produced between 1902 and 1909
  • Simplex Typewriter Company, an index typewriter manufacturer
  • A trade name used by British railway locomotive manufacturers The Motor Rail & Tramcar Co Ltd
  • The trade name of the swinging-tray record changer used in Wurlitzer jukeboxes from the 1930s to the 1950s
  • A brand of fire alarm systems made by SimplexGrinnell
  • A manufacturer of jacks used in railroads and mining industries, now owned by Actuant Corporation

Linguistics

  • A monomorphemic form of a word that is not a part of a compound or derivational affixes

Mathematics

  • Simplex, a term in geometry meaning an n-dimensional analogue of a triangle
  • Simplicial polytope, a polytope with all simplex facets
  • Simplicial complex, a collection of simplicies
  • Pascal's simplex, a version of Pascal's triangle of more than three dimensions
  • Simplex algorithm, a popular algorithm for numerical solution of linear programming problems
  • Simplex graph, derived from the cliques of another graph
  • Simplex noise, a method for constructing an n-dimensional noise function
  • Simplex plot, a ternary plot used in game theory

Technology

  • Simplex communication, a one-way communications channel
  • Simplex signaling, signalling in which two conductors are used for a single channel
  • Simplex, using a single frequency for transmit and receive instead of an amateur radio repeater
  • SimpleX Chat, a privacy focused messaging application
  • Simplex printing, printing one sided pages, a technique that is contrast to duplex printing
  • Small Innovative Missions for Planetary Exploration (SIMPLEx) program at NASA