June 1993 – The “Common Desktop Environment” was a joint venture with Sun, HP, IBM and the Unix System Laboratories. Based on X11 and Motif, CDE was heavily based on HP's VUE (“Visual User Environment”) that debuted in 1988. It included a dock-like “Front Panel,” virtual desktops, re-sizable windows and was a modern and powerful desktop environment. CDE was the king of graphical environments for UNIX throughout much of the 1990's, and became Open Source in 2012.
Interesting Related Tidbit: The same month CDE was announced, “Unix System Laboratories” was purchased by Novell from Bell Labs. Remember the big “SCO v. Novell” case? This is where Novell picked up the rights to UNIX.