The SHARE Operating System (SOS) is an operating system introduced in 1959 by the SHARE user group.
The main objective was to improve the sharing of programs.
The SHARE Operating System provided new methods to manage buffers and input/output devices.
Like GM-NAA I/O, it allowed execution of programs written in assembly language.
A series of articles describing innovations in the system[1] appears in the April 1959 Journal of the Association for Computing Machinery.