Working at OCTO Technology, a few months ago I published an article about graph processing on our corporate blog. Soon after, somebody suggested it appear on DZone's Big Data portal. So here it is :-)
The article gives an overview of the use of BSP (Bluk-Synchronous Parallel), an algorithm often used for processing of such large graphs. Then it explores a list of products and frameworks dedicated to graph processing, either using BSP or based on other approaches.
The full article can be found on our blog.