SCO may refer to one of two possible, but distinct, companies:
SCO Group - Company originally known as "Caldera Systems", which acquired several things from Santa Cruz Operation in 2001. Among those: source code for UNIX, two divisions of the former Santa Cruz Operation, and the "SCO" trademark. Caldera later changed its name to "SCO Group".
Santa Cruz Operation - Company founded in 1979, which sold a major division and its namesake trademark in 2001, and renamed itself "Tarentella"
