28 October 2003 SCO Group has claimed that the open source General Public License (GPL) is “unenforceable, void or voidable” and further suggested that “IBMs claims are barred by fraud, illegality, collusion, conspiracy and/or lack of clean hands”.

The claims are made in the latest filing in the legal action it launched in March against IBM over the system giant’s contributions to Linux, which SCO claims violate its Unix intellectual property.

“[SCO] admits that the GPL purports to guarantee the right to freely share and change free software, but denies that the GPL applies to any program whose authors commit to using it [and] denies [the] enforceability or applicability of the GPL”.

SCO is forced to try and use the case to overturn the GPL as all the technologies it has claimed infringe its own intellectual property have been released under the GPL by SCO itself, both when it was called Caldera and after Caldera acquired Santa Cruz Operation’s Unix server and services businesses in 2001 and renamed itself SCO Group.

However, eight months after launching its original legal action against IBM, SCO still has not fully disclosed the precise areas of the Linux operating system that it says infringe its intellectual property.

Nor, despite suggesting that “millions” of lines of code have been copied from SCO’s Unix operating system to Linux has it been able to point to more than a handful of infringing lines, which open source advocates have examined and suggested are included in Linux legitimately.

SCO has so far stalled on “motions to compel discovery”, a legal filing that would compel SCO to spell out its claims, filed by IBM.

SCO’s claims are further clouded by a 1992 intellectual property infringement case by AT&T, the inventors of Unix, against the makers of BSD, a free Unix-like operating system that had originally been developed at the University of California at Berkeley in the 1980s.

That case found that Unix contained far more code taken from sources such as BSD, rather than the other way round, and ended in humiliating defeat for AT&T.