Software patents are a huge potential threat to the ability of people to work together on open source. Making it easier for companies and communities that have patents to make those patents available in a common pool for people to use is one way to try to help developers deal with the threat.
When it comes to software, I much prefer free software, because I have very seldom seen a program that has worked well enough for my needs, and having sources available can be a life-saver.
