In a statement released Monday, the Lindon, Utah-based company--which is embroiled in a legal battle with IBM over Linux--said it has received copyrights to Unix and will enforce its ownership of the System V code by requiring customers to license SCO UnixWare, executives said.
The decision undermines claims made by Novell in late May that it, not SCO, has ownership of Unix System V copyrights.
With copyrights in hand, SCO said it will authorize companies to run binary code and applications based on Linux 2.4x kernels and higher only if they license SCO's UnixWare proprietary operating system.
If enforced, the action would in effect nullify one of the greatest attributes of open-source software--that it can be used for free. Proprietary operating systems such as Unix and Windows, in contrast, typically cost customers millions of dollars to license.
This is the latest move by SCO to wrestle royalties from Linux. Last month, SCO--which incorporates former Linux company Caldera Systems--formally revoked IBM's license to sell AIX. However, sources said it will be up to the courts to determine whether these actions are enforceable.
The dispute started in March when SCO filed a lawsuit against IBM claiming that IBM had misappropriated Unix code and donated it to the Linux open-source project. IBM has a contract with SCO for the Unix System V code used in its AIX Unix operating system.
IBM denies SCO's claims and vows to fight all claims in court.
According to SCO's statement Monday, software code that allows Linux to be run on servers with multipe processors was "misappropriated" from Unix System V.
"Hundreds of files of misappropriated Unix source code and derivative Unix code have been contributed to Linux in a variety of areas, including multiprocessing capabilities," the statement said. "The Linux 2.2.x kernel was able to scale to two to four processors. With Linux 2.4.x and the 2.5.x development kernel, Linux now scales to 32 and 64 processors through the addition of advanced Symmetrical Multi-Processing capabilities taken from Unix System V and derivative works, in violation of SCO's contract agreements and copyrights."