Linux kernel an SCM system which satisfied Torvalds' technical requirements. BitKeeper was made available to Linus and several others free of charge but was not free software, which was a source of controversy. The system did provide some interoperability with free SCM systems such as CVS and Subversion. In April 2005, efforts to reverse-engineer the BitKeeper system by Andrew Tridgell led BitMover, the company which maintained BitKeeper, to stop supporting the Linux development community. In response, Torvalds and others wrote a new source code control system for the purpose, called Git. The new system was written within weeks, and in two months
SHARE Operating System SHARE Operating System The SHARE Operating System (SOS) was created in 1959 as an improvement on the General Motors GM-NAA I/O operating system, the first operating system, by the SHARE user group. The main target was to improve the sharing of programs over GM-NAA I/O. SHARE Operating System provided new methods to manage buffers and input/output devices, and, like GM-NAA I/O, allowed execution of programs written in assembly language. Initially, it worked on IBM 709 computer and its transistorized compatible successor the IBM 7090. A series of articles describing innovations in the system appears in the April, 1959, Journal of