DIMACS Implementation Challenges
Here you will find The Famous DIMACS Graph Format , which is also accepted by GraphInsight.
From the webpage:
Quite a few research papers have been referring to the DIMACS graph format. The first Challenge used networks (directed graphs with edge and node capacities) and undirected graphs (for matching), and the second Challenge used undirected graph. Extending these formats to directed graphs should be straightforward. Specifications for the Challenge 1 formats are available by anonymous ftp (or through the DIMACS web page Previous Challenges) in
The implementation challenges page lists several other challenges with a rich supply of materials, including “other” graph formats.
The challenges page is just a sampling of the resources located at DIMACS (homepage).