Lessons To Learn
A person can commit copyright infringement even without knowing that the work was subject to copyright, so even unintentional infringers don't get a free pass under copyright law. Thus, the open source community's success requires that every contributor understand copyright law and provide only non-infringing code. A single bad apple can spoil the barrel.
In this case, Linux's usability depends on IBM's judgment to contribute some AIX code to it. If IBM misjudged its legal rights to make that contribution, all downstream users of Linux may bear the consequences.
Software end users take on some legal risk of infringement in every software license they accept. However, while a software vendor has significant financial incentive to manage this risk, the open source community's diffuseness makes it harder for open source end users to know what they're getting. Therefore, end users of open source software need to choose their software knowledgeably.
IBM's role in the dispute also prompts a lesson. If IBM contributed code to Linux but lacked the legal rights to do so, it unwittingly exposed itself to legal liability. Proper diligence of software is necessary before deciding to contribute software to the open source community.
SCO's actions suggest two other lessons. First, SCO purchased assets with a complex chain of title. While this is not inherently a problem, the messy history does raise the possibility that one or more of the transactions along the way didn't transfer all of the rights to the code, leaving SCO with some risk that its lawsuit will unravel as more questions are asked about each step in the chain of title. Therefore, thorough diligence is warranted before bringing a lawsuit over assets with a complex past.
Second, SCO's claim that UNIX is protected by a trade secret is substantially undercut by prior distributions of the purportedly secret code. Thus, decisions to post source code to the web should be considered for their consequence on IP protection.
In light of these lessons, regardless of who wins or loses the lawsuits, we may all be a little wiser about managing software assets and using open source software based on the war over UNIX.