"The SCO Group's attempts to squeeze a revenue stream out of Linux is rooted in the long and tangled history of computer operating systems.
"Unix is among the oldest and most reliable operating systems. Developed in the late 1960s and early '70s at AT&T's Bell Laboratories, Unix was never seen as a cash cow for Ma Bell.
"In fact, AT&T liberally licensed it to several companies and shared it with universities for educational purposes. Companies created their own flavors of AT&T's Unix, called System V, and rebranded them with names like IBM's AIX, Hewlett-Packard's UX and Sun Microsystems' Solaris..."