Like Iraq’s weapons of mass destruction, however, SCO’s evidence of Unix System V code in Linux has proved elusive and the question of Unix code in Linux has slipped further and further from court. As Linux users, developers and vendors continue to go about their business, SCO’s search for code of mass destruction will have to continue if SCO is to convince the world that it did not launch its war against Linux on a false premise.

As SCO’s allegations against Linux have moved into the courts, the claims that Unix System V code has been literally copied into Linux have faded however, while instead the company is focusing its efforts on contract disputes, with legal wrangling about who was allowed to do what with which code.

The process began when SCO upped its claim against IBM to $5 billion in February 2004, while simultaneously dropping its claim that IBM had misappropriated its trade secrets and contributed System V code to Linux, focusing instead on an alleged breach of contract from its contribution of AIX and Dynix code.

SCO continued to state that Linux contained its copyrighted materials, however, and in March launched legal action against Linux user AutoZone apparently designed to prove just that. SCO’s positioning of the case and listing of Unix System V copyrights in its complaint against AutoZone, led many to believe that SCO’s copyright claims against Linux would be covered by the AutoZone case, especially when SCO in April asked the court to dismiss or stay IBM’s request for a declaratory judgment that its Linux activities do not infringe SCO’s copyright until the completion of its case against AutoZone.

While characterizing SCO’s case against AutoZone in an early hearing last week, SCO’s lawyer seemed to take a different view. David Stone of SCO’s law firm Boies, Schiller and Flexner stated: End users of Linux who have previously been SCO customers, such as AutoZone, which used OpenServer, are migrating to Linux. There are many issues which can arise in this migration process which don’t necessarily have to do with what’s in Linux.

Stone went on to explain that it was SCO’s belief that AutoZone had violated the copyright of its OpenServer libraries in migrating to Linux, as opposed to violating its Unix copyright by running Linux.

With the judge having delayed SCO’s case against AutoZone until the completion of the IBM litigation, the subject of Unix System V copyright violation in Linux is further from being resolved in any case, with Linux users and vendors free to go about their business for the foreseeable future.

Attempting to explain the difficulty of identifying and discovering weapons of mass destruction, US defense secretary Donald Rumsfeld famously alluded to known and unknown knowns and unknowns.

SCO appears to be following a similar line, if not in attempting to identify Unix code in Linux, then in its failed legal case against DaimlerChrysler, which it also sued in March alleging that the company had breached an enterprise Unix source license agreement with the firm by not certifying that it was keeping to the terms of its license agreement.

The car giant responded by saying that it had not used SCO’s software for over seven years, and therefore could not list any CPUs on which the licensed software is being used. The judge all but threw the case out of court.