At long last, the SCO Group's ugly, often farcical legal crusade against Linux appears to be over.

SCO has spent four and a half years arguing that it owns the copyrights to Unix, and that the free Linux operating system includes code stolen from Unix.

Its claims suffered what is likely a death blow Friday when a judge in Utah ruled that SCO does not, in fact, own the copyrights to Unix.

SCO issued a statement saying it would carry on with other claims against Novell, and hinted that it might try to appeal Friday’s ruling.

Passionate fans of Linux, a free operating system developed collaboratively by programmers from around the world, have argued from the start that SCO’s claims lacked any merit. On pro-Linux Web sites, they’ve been celebrating since Friday, viewing the ruling as vindication.

For SCO, it’s a fizzle of an ending to a case that began with loads of bluster and bravado. In March 2003, SCO Group, a tiny company based in Lindon, Utah, sued IBM, claiming IBM took code from Unix and put it into Linux. SCO also warned hundreds of customers that they might be in legal trouble for using Linux.

The suit got more complicated when Novell, an IBM ally, stepped forward and said that Novell, not SCO, actually owned the Unix copyrights. Novell had licensed Unix to SCO’s predecessor company, and SCO argued that in this transaction it had picked up the copyrights to Unix. Novell, however, claimed it had retained copyrights to Unix code.

Before SCO could pursue its case against IBM it had to sue Novell to establish its ownership of the Unix copyrights.

The trial was set to begin in September. But on Friday a federal court judge issued a summary judgment declaring that Novell owns the copyrights.

In a statement, SCO said it was “obviously disappointed with the ruling,” but also indicated it intends to carry on with its lawsuit against Novell. “Although the district judge ruled in Novell's favor on important issues, the case has not yet been fully vetted by the legal system and we will continue to explore our options with respect to how we move forward from here.”

Novell, in a statement, said: “The court's ruling has cut out the core of SCO's case and, as a result, eliminates SCO's threat to the Linux community based upon allegations of copyright infringement of UNIX. We are extremely pleased with the outcome.”

IBM did not respond to a request for comment before this story was published.

SCO’s claims against Linux angered the passionate fans of the free operating system, prompting pickets outside SCO’s offices and loads of heated invective. Linux is arguably the biggest thing to happen in computing in the past 20 years. Its fans are celebrating now.