When we talk of free software, we typically think of things like GNU/Linux, Apache or Firefox. But one aspect that often gets overlooked is that of multimedia codecs. There's a good reason for this: most of them are patent-encumbered, which makes using them with free software hard - well, hard if you want to do it legally. In practice, most people have employed implementations of dubious legality, and the licensors have taken the sensible view that they are hardly losing millions from this kind of activity, and have turned a blind eye.
On Open Enterprise blog.