This dissertation by Tim Purcell of Stanford University discusses several topics relevant to GPGPU including a stream processor abstraction for GPUs, and GPU-based ray tracing and photon mapping algorithms. Much of this work has been reported on GPGPU before, but the description of the ray tracing work in particular is expanded and updated from previous papers with details about the Radeon 9700 ray tracer demonstrated at Siggraph 2002. Included on the web page are links to the dissertation defense talk slides and movies of the various demos. (Ray Tracing on a Stream Processor, Timothy J. Purcell, Ph.D. Dissertation, March 2004.)