IBM is demanding information from Microsoft, Hewlett Packard, Sun Microsystems and BayStar Capital as part of its defense against the SCO Group's lawsuit claiming that Big Blue used SCO's version of Unix code in its version of Linux.
IBM filed four subpoenas in U.S. District Court of Utah, where the case is being heard, to obtain information about the four companies' involvement with SCO. The companies are expected to provide depositions to meet the requests, which are posted on Groklaw.
SCO sued IBM in March 2003, claiming the computer giant used its code in its modifications and distribution of Linux and violated SCO's intellectual property rights. IBM denies the allegations. Novell also claimed it owned copyrights on the code, triggering another suit. In August 2003, IBM filed a countersuit against SCO.
Big Blue is requesting agreements, communications and records regarding the companies' use of Unix code, their contributions to Linux and their relationships with SCO.
Microsoft and Sun have paid millions for Unix licenses. BayStar invested $50 million in SCO in 2003, before the company began making changes.
Of all the companies involved, only SCO, IBM and HP could be reached for comment. However, spokespeople for both IBM and HP declined to comment, saying it was an ongoing legal matter. Other companies did not return calls seeking comment Thursday.
SCO spokesman Blake Stowell said the subpoenas are a normal part of the discovery process.
"We're fine with whatever it is they want to try to find out," he said. "We're a fairly open book when it comes to those relationships."
The case is expected to go to trial in a year, Stowell said.