SCO operating systems are no longer supported due to their recent
(and absurd) attacks against Linux and IBM. Bug reports relating to
UnixWare will be ignored, or possibly even laughed at derisively.
Note that I have no reason to believe anyone has ever used Nmap on
SCO systems. Unixware sucks.

http://www.insecure.org/nmap/nmap_changelog.html

Go NMAP, Fu*k SCO