The document summarizes preliminary results from a project comparing the performance of open source implementations of Pregel and related graph processing systems (Hama, Giraph, GPS) on single-source shortest path (SSSP) and PageRank algorithms. Initial results show that Hama does not scale well to larger graphs, while Giraph and GPS scale better. Further analysis of memory usage, network traffic, additional systems like GraphLab and Signal/Collect, and using Green-Marl to generate code for Giraph and GPS is still in progress.