SunOS from Sun Microsystems (became Solaris)

SunOS is a version of the UNIX operating system developed by Sun Microsystems for workstations and servers of its own production. The name SunOS is usually used to refer to versions 1.0 through 4.1.4. These versions were based on the BSD version of UNIX, while SunOS version 5.0 and later is based on UNIX System V of the fourth release (SVR4) and appears under the name Solaris.