The following paper discusses the SSSP implementation submitted to the 9th DIMACS Shortest Paths Challenge:

K. Madduri, D.A. Bader, J.W. Berry, and J.R. Crobak. An experimental study of a parallel shortest path algorithm for solving large-scale graph instances. In Proc. 9th Workshop on Algorithm Engineering and Experiments (ALENEX 2007), New Orleans, LA, January 2007. SIAM.

The source code for the SSSP implementation discussed in the paper is available here (last updated in September 2006). Please contact Kamesh Madduri for the latest version.