Unix System V

The company claims that code from its Unix System V code base has been illegally copied into Linux.

Meanwhile, hostilities between SCO and another former owner of the Unix System V code, Novell, appear to be back on again after the Provo, Utah-based network software vendor confirmed that it had applied for and received copyright registrations pertaining to Unix.

Silicon Graphics Inc's VP of software, Rich Altmaier, has responded to claims by SCO Group Inc that SGI has breached the terms of its Unix license, and has rejected the suggestion that its XFS file system technology is a derivative work of SCO's Unix System V code.

In fact, our Unix license clearly provides that SGI retains ownership and all rights as to all code that was not part of AT&Ts Unix System V."

This code has been used by SCO as apparent evidence to support its claims that Linux contains over a million lines of its Unix System V code, but has been dismissed by the open source leader Bruce Perens as being available under the open source BSD license.

It is not clear what SGI has to do to remedy the violations alleged by SCO, although given SCO's attempt to license its Unix System V code to systems and software vendors, acquiring a new Unix license from the company probably would not hurt.

In March SCO launched what has now escalated to a $3bn lawsuit against IBM for breach of contract and misappropriation of trade secrets, accused the company of contributing Unix System V code into Linux, and gave the company 100 days notice of the termination of its Unix license.

That deadline passed on April 13 without a response from IBM prompting SCO to file an amendment to its original lawsuit asking the US District Court of Utah to compel IBM to stop using and distributing AIX and to destroy or return all copies of Unix System V to SCO.