Linux wars: Big Blue strikes back

IBM's assertion came in a message to its sales force Thursday evening, four days after SCO said Linux users must pay the company for a Unix license or face possible legal action. SCO Group, owner of the Unix intellectual property, contends that Unix code was illegally copied line by line into Linux and that companies such as IBM illegally transferred improvements made to Unix into Linux.

SCO's latest actions broadened its case against Linux beyond the $3 billion lawsuit it has filed against IBM. Likewise, IBM's new message to its sales force--the chief way it communicates with customers--is a significant expansion of its defense over the narrower memos it sent earlier. Those memos said that IBM will stand by its customers and defend itself vigorously.

"SCO itself has distributed Linux under the GNU General Public License (GPL), which grants a free copyright license and requires that users be granted the right to freely redistribute the code free of claims," Bob Samson, vice president of IBM's systems sales, said in the message, which was seen by CNET News.com. IBM confirmed the authenticity of the memo. "SCO has not explained how it can now make a claim in the face of its distribution of Linux under these terms," Samson said.

However, SCO has in fact addressed the issue, in response to claims by Linux seller and former business partner SuSE and by the Free Software Foundation, which wrote the GPL. On Friday, SCO spokesman Blake Stowell reiterated the company's earlier position that the GPL provisions don't apply because SCO is the Unix copyright holder and it never placed the copyrighted code under the GPL.

"Distributing a product is not the same as contributing to a product," Stowell said Friday. In other words, the mere act of distributing GPL-covered code isn't sufficient; the copyright holder also has to deliberately release the code as open-source, he said. "The copyright holder has to knowingly contribute this code."

Section 0 of the GPL states, "This license applies to any program or other work which contains a notice placed by the copyright holder saying it may be distributed under the terms of this General Public License." However, Section 6 states, "Each time you redistribute the program (or any work based on the program), the recipient automatically receives a license from the original licensor to copy, distribute or modify the program."

Legal experts said it's not clear which side is in the right, and that it may take a legal challenge in court to produce a ruling.

In the message from IBM, Samson also disparaged SCO's efforts to extract Unix license revenue from Linux users.

"This appears to be another desperate, unfair and unsupported attack on Linux in an attempt to wring money from customers without providing any factual basis as to why they should pay," Samson said. "SCO's statements consist of bare allegations without supporting facts. SCO has yet to identify the code which it claims is infringing in Linux, nor has it offered to openly disclose the code to the Linux community."

SCO hasn't identified publicly what code was allegedly copied line by line from Unix, though it has shown it to more than four dozen people who signed nondisclosure agreements, Stowell said.

SCO has, however, given some examples of software it said was derived from Unix and moved to Linux in violation of its contracts with Unix licensees such as IBM. In its lawsuit against IBM, SCO points to read-copy update (RCU), the Journal File System (JFS) and extensions to support non-uniform memory access (NUMA). These software packages are used to bring various higher-end features to Linux.

IBM contends it has done nothing wrong and hasn't violated its license terms.