Semaphore (disambiguation)

Semaphore is the use of an apparatus with telegraphy to create a visual signal transmitted over long-distances.

It may refer more specifically to:

Flag semaphore
Semaphore telegraph, a system of long-distance communication based on towers with moving arms
Railway semaphore signal for railway traffic control
Traffic semaphore, another name for automotive traffic lights based on their early resemblance to railway semaphores
Turning semaphore or trafficators, retractable arms to indicate turns on automobiles from the 1920s to 1950s

Other

Semaphore (programming), in computer science, a mechanism for supporting mutual exclusion in concurrent programs
Semaphore (software), a continuous integration testing utility
Semaphore, South Australia, a historic seaside suburb of Adelaide
Semaphore railway line, Adelaide, a closed railway line in South Australia
Semaphore Corporation (company), a software and publishing firm that operated from 1982 to 2017
Semaphore (album), a 1998 album by Fridge
"Semaphore" (song), a 2004 single by the New Zealand band Jakob
Semaphore, fictional professor in Cubitus comic strips or Wowser cartoons