SAN FRANCISCO (MarketWatch) -- A federal judge's ruling Friday may help proponents of Linux open-source software sidestep a significant legal threat. SCO Group Inc. does not own the copyright to Unix operating-system software, as it had claimed, and Novell Inc. is the proper owner, U.S. District Judge Dale Kimball said in a filing in federal court in Utah. SCO Group had sued Novell in 2004 for falsely claiming ownership of Unix. In 2003, SCO Group filed a high-profile lawsuit against International Business Machines Corp. for contributing code to Linux open-source software that it said included some of SCO's Unix-related intellectual...