Solaris, formerly known as SunOS, is a trademarked UNIX operating system derived from 4.4BSD-Lite and System V Release 4. It's a combination of BSD, SVR4, and proprietary Sun code, and it currently powers most of the world's 64-bit workstations. It was originally designed for the SPARC and UltraSPARC platforms, but it has moved into the x86 market as well and there will be an AMD64 port possibly as early as Q1 2004.