SunOS is an older text-based UNIX that runs on Sun SPARC. (http://wwws.sun.com/software/solaris/ Solaris) is an enhancement of SunOS that includes a graphic user interface.

SunOS 4 supports 1 processor per system except in some very old configurations (4/6xx series machines with slow processors). SunOS 5 supports up to 64 processors in a single box (the E10000, for example). —Greg Onufer