The roots of both disputes date back to February 1985 when IBM entered into a licence agreement with the then owner of the UNIX system, AT&T, in order to produce its own AIX operating system. The agreements required that IBM hold the UNIX software code in confidence, and prohibited unauthorised distribution or transfer.
In 1992, AT&T sold UNIX to Novell. Then, in 1995, the Santa Cruz Operation purchased rights in UNIX from Novell, including source code, source documentation, software development contracts, licenses and other intellectual property.
The initial contract specifically excluded copyright from the sale, while an amendment, dated in October 1996, again specifically excluded copyrights, with the exception of "the copyrights and trade marks owned by Novell as of the date of the [contract] required for Santa Cruz Operations to exercise its rights with respect to the acquisition of UNIX and Unixware technologies."
The Santa Cruz Operation sold on these rights to Caldera International, which subsequently changed its name to The SCO Group.
In March last year SCO sued IBM, accusing Big Blue of letting parts of UNIX 'slip' into the Linux operating system in breach of SCO's rights. SCO originally sued IBM for $1 billion, increased the claim to $3 billion, and then gained approval for another increase to $5 billion.
IBM counterclaimed, arguing firstly that SCO is in breach of the General Public Licence, or GPL, which underpins the distribution of most open source software, and then accusing SCO of infringing IBM's own intellectual property rights. Until Thursday, SCO was seeking to have these infringement claims split off into a separate action.
In April this year, IBM asked the District Court in Salt Lake City to declare that it has not infringed any SCO copyright through its Linux activities – an attempt by Big Blue to short circuit the most controversial development in the history of open source software.
Last month IBM followed this up with a motion for summary judgment – i.e. judgment without trial – arguing that SCO has produced no evidence of copyright infringement and should therefore not be allowed to proceed with the claim. The court has not yet ruled on this issue.
Meanwhile SCO and Novell have become embroiled in a separate action, concerning the exact scope of the rights acquired by SCO in 1995.
Initially, SCO claimed to own patents in UNIX; now it talks only of copyrights and "other" intellectual property rights. But Novell, a Linux distributor in its own right, still believes that it still owns important copyrights in the UNIX system, and has publicised the fact.
In January, SCO filed suit against Novell, alleging that:
Rulings in both cases were issued last week, with mixed results for SCO.
Judge Dale Kimball of the US District Court in Utah, presiding in both actions, ruled that the trial for the IBM case could be pushed back to November 2005, as requested by SCO, but he denied SCO's request that IBM's counterclaim of patent infringements by SCO be split off into a separate action.
Judge Kimball then ruled against SCO in the Novell action, denying the company's request that the case be moved to a state court – where the legal requirements are less stringent. But Kimball also denied Novell's request to dismiss the case out of hand.
More information on the SCO saga, including copies of the latest SCO and IBM rulings, is available at Groklaw.net