For my Bachelor Thesis in Computer Science I made this C++ ray tracing engine, appropriately titled RayEngine. It can render several scenes and effects in real-time (shadows, reflections, refractions and ambient occlusion) to create some very realistic images. The program can be downloaded from the Github page (requires 64-bit Windows).
Even if you can't run it, you can still take a look at the thesis paper. It contains a crash course in computer graphics and ray tracing, a description of the program features, benchmarks performed on a high end CPU and GPU and a discussion of the results.