Nauty (Popularity: ): A program for computing automorphism groups of graphs and digraphs. It can also produce a canonical labelling. The LEDA Library (Popularity: ): LEDA is a library of the data types and algorithms of combinatorial computing. plantri and fullgen (Popularity: ): Programs for generation of certain types of planar graph, generated in such a way that exactly one member of each isomorphism class is output without the need for storing them. Algorithms and Software for Partitioning Meshes (Popularity: ): Using combinatorics to solve structured linear systems of equations. METIS: Family of Multilevel Partitioning Algorithms (Popularity: ): Graph, mesh, and hypergraph partitioning software. SF, Posets and Coxeter/Weyl (Popularity: ): John Stembridge's Maple packages for symmetric functions, posets, root systems, and finite Coxeter groups. Combinatorics Software of the Algorithms Project (Popularity: ): Combinatorial analysis, discrete mathematics and computer algebra are the main interests of the Algorithms Projects. The packages let you define combinatorial structures; manipulate the associated generating functions, functional equations or ... LINK: A Software System for Discrete Mathematics (Popularity: ): A general-purpose, extendible computing environment in which discrete mathematical objects representing real world problems can be easily manipulated and visualized. Graph Coloring By DSATUR (Popularity: ): By using the DSATUR algorithm, this php/form colors any graph in the Dimacs format. JGraphT (Popularity: ): Free Java class library that provides mathematical graph-theory objects and algorithms.