I seen that Red Hat has recently found themselves ensnared in a patent lawsuit stemming from their purchase of JBoss. The lawsuit is centered around the Hibernate 3 technologies — or technologies that deal with object-oriented access to a relational database. The story can be found here: http://www.infoq.com/news/RedHat-Sued-Due-to-Hibernate-3-O
My assumption, looking over this lawsuit, is that there will likely be much prior art to pull from to hopefully invalidate this particular claim. However, in a worse case scenero (i.e., the patent is upheld), frameworks made popular by languages like Ruby and Python would be instant targets and likely need to be quickly changed. In fact, much of the open source software that interacts with databases is build around this modelled approach — and would have to be changed.
Given my current interest in Ruby and Rails, I’ll likely be keeping an eye on this particular lawsuit. Unfortunately, I think that its likely a sign of things to come within the Open Source community. I see a time coming very soon where large litigation factories are going to start suing developers or distributors as a way marginalizing Open Source software (which pays no IP fees) and proping up proprietary software shops (that likely do pay the IP fees).