DEX is a high performance library to manage very large graphs or networks. DEX is a product with an origin in the research that DAMA-UPC is carrying out. Since March 2010 DEX is developed, supported and commercialized by Sparsity-Technologies http://www.sparsity-technologies.com, a spin-out of UPC.
At a more detailed level, DEX allows to store a labeled and directed attributed multigraph. A labeled graph has a label for each node and edge, that it is used as the type for that node or edge. A directed graph allows for edges with a fixed direction, from the tail or source node to the head or destination node. An attributed graph allows a variable list of attributes for each node and edge, where an attribute is a value associated to a name, simplifying the graph structure. A multigraph allows multiple edges between two nodes. This means that two nodes can be connected several times by different edges, even if two edges have the same tail, head and label.
DEX is available for free evaluation at http://www.sparsity-technologies.com/dex_downloads. Take some time to play with it and develop your applications to manage the network like data structures that represent your network of friends, or your network of information.
Martínez-Bazan, N., Muntés-Mulero, V., Gómez-Villamor, S., Nin, J., Sánchez-Martínez, M., and Larriba-Pey, J. 2007. Dex: high-performance exploration on large graphs for information retrieval. In Proceedings of the Sixteenth ACM Conference on Conference on information and Knowledge Management (Lisbon, Portugal, November 06 - 10, 2007). CIKM '07. ACM, New York, NY, 573-582.