IRIX is a UNIX -based operating system from SGI that is optimized for applications that use 3-D visualization and virtual reality environments. IRIX is compatible with UNIX System V, Release 4 and all standards of The Open Group .
By integrating OpenGL (Open Graphics Library) with the X Window System , IRIX offered the first real-time 3-D X Windows environment. IRIX was also the first commercially available UNIX-based operating system to support symmetric multiprocessing ( SMP ) and a complete 64-bit and 32-bit environment. Every SGI computer uses the IRIX operating system.