SunOS
SunOS was the version of "Unix" used by Sun Microsystems for their workstations that debuted in 1992. After the release of SunOS 4 Sun changed over from using BSD code to using licensed System V code and named the operating system Solaris version 2. SunOS was then retroactively named Solaris 1.x. Some people still refer to Solaris as "SunOS" despite both of them being quite different.
See also
Categories: Computer stubs