12 June 2003 SCO Group CEO Darl McBride has reiterated his threat to revoke IBM’s Unix licence if the company does not cave in to his demands by midnight on Friday. The move would technically make it illegal to run applications on IBM’s AIX Unix operating system — potentially affecting tens of thousands of IBM customers worldwide.

IBM has maintained its silence on the matter and has not revealed whether it is in talks with SCO to settle the matter — or whether it will pursue the matter through the courts.

McBride, however, is insistent. “If we don’t have a resolution by midnight on Friday the 13th, the AIX world will be a different place,” McBride told Reuters. He added: “People will be running AIX without a valid licence”.

SCO is suing IBM for $1 billion for allegedly copying Unix technologies from AIX to Linux. IBM originally bought its Unix licence from AT&T, the original developer of Unix, in 1985 in order to build its first version of AIX. AT&T subsequently sold its Unix operating systems, copyrights and patents to Novell in 1993 after losing a bitterly contested court case in which it had accused the developers of the free BSD version of Unix of copyright and patent infringement.

However, the courts concluded that the intellectual property was barely enforceable because of the amount of copying from free Unix developments, particularly BSD, into Unix — not the other way round as AT&T had asserted.

McBride added that SCO has settled most of its outstanding differences with Novell, the previous owner of SCO’s UnixWare operating system product, which still holds the original Unix patents.

Two weeks ago, Novell had claimed that it and not SCO also owned the Unix copyrights — until a SCO para-legal dug out a 1996 document suggesting a transfer of ownership a year after SCO had bought UnixWare. It is, however, still unclear whether that transfer was ever registered at the US Copyright Office.