I've been working a lot with the libsurvive project to get this project going. It's very well aligned, and a small community of awesome hackers has converged on that project, as well as getting some unofficial support from the Valve guys from time to time. My main area of focus has been on finding the pose of a tracked object given the angle data from the lighthouse. This has been a much bigger undertaking than I ever imagined. I finally have pose estimation working at a somewhat usable level.