Topic summary
SCO Open Desktop

Extracted from the Wikipedia article OpenServer.
SCO UNIX/SCO Open Desktop
In 1987 AT&T Corporation, Microsoft, and Sun Microsystems agreed to combine their versions of the Unix operating system. Santa Cruz Operation (SCO) sublicensed Microsoft's Xenix and wanted to retain the Xenix name, but AT&T said "If they want to call it Unix, they've got to use it the way it is. We don't want another set of variants".