I took a look at the Google summer of code mentoring organizations for 2008 and was surprised to see BBC research listed. They were probably previous participants but it seems that BBC maintains a number of open source projects on their open source page. The most notable ones seem to be the ones that they are going to use the interns for, Kamaelia, which is apparently a test system for large scale media distribution, and Dirac, an open source video codec. All in all, some pretty cool stuff.