SCL - star complement library
- A program for calculating the maximal graphs using the star complement technique. The programs for computing the maximal cliques and isomorphism classes of graphs are included.
- http://www.matf.bg.ac.yu/%7ezstanic/scl.htm

graph-utils
- A set of small utilities realizing theoretical graph algorithms (including tree algorithms). The utilities work with simple text input/output formats.
- http://graph-utils.sourceforge.net

Graph Partitioners
- Three algorithms written in NESL for finding separators of graphs, in order to compare the quality of the cuts.
- http://www.cs.cmu.edu/~scandal/alg/separator.html

Graph Magics
- A tool for graph theory, having a generator and offering various algorithms: shortest paths, network flows, maximal clique, optimal coloring etc.
- http://www.graph-magics.com

Project Vega
- A system for manipulating discrete mathematical structures: a Mathematica based collection of operations with interface to external packages and programs.
- http://vega.ijp.si/Htmldoc/Vega03.html

ACE
- An Algebraic Combinatorics Environment for MAPLE providing functions to work with classical structures in algebraic combinatorics. Free download.
- http://phalanstere.univ-mlv.fr/~ace/ACE/3.0/ACE.html

GOBLIN Graph Library
- C++ library of graph optimization algorithms with a GUI for editing, running and tracing the algorithms.
- http://www.math.uni-augsburg.de/opt/goblin.html

GRAPE
- A GAP package for computing with graphs; primarily designed for the efficient construction and analysis of graphs related to groups, combinatorial designs and finite geometries.
- http://www.maths.qmul.ac.uk/~leonard/grape/

Information System on Graph Class Inclusions
- A java applet for researching what is known about particular graph classes.
- http://wwwteo.informatik.uni-rostock.de/isgci/

GeoSteiner
- Software for computing Steiner trees. Written in ANSI C, includes the public domain LP-solver lp_solve.
- http://www.diku.dk/geosteiner/

JGraphT
- Free Java class library that provides mathematical graph-theory objects and algorithms.
- http://jgrapht.sourceforge.net

LINK: A Software System for Discrete Mathematics
- A general-purpose, extendible computing environment in which discrete mathematical objects representing real world problems can be easily manipulated and visualized.
- http://dimacs.rutgers.edu/~berryj/LINK.html

GraphThing
- Tool for investigating Graph Theory, with a GTK interface. Free under GPL. Unix, source code in C++.
- http://graph.seul.org/

Combinatorics Software of the Algorithms Project
- 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 recurrences;
- http://algo.inria.fr/libraries/software.html

SF, Posets and Coxeter/Weyl
- John Stembridge's Maple packages for symmetric functions, posets, root systems, and finite Coxeter groups.
- http://www.math.lsa.umich.edu/~jrs/maple.html

METIS: Family of Multilevel Partitioning Algorithms
- Graph, mesh, and hypergraph partitioning software.
- http://www-users.cs.umn.edu/~karypis/metis/

Algorithms and Software for Partitioning Meshes
- Using combinatorics to solve structured linear systems of equations.
- http://www.cs.sandia.gov/CRF/chac.html

plantri and fullgen
- 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.
- http://cs.anu.edu.au/people/bdm/plantri/

Gato: The Graph Animation Toolbox
- Software for visualizing graph algorithms. Free under GPL. Unix, Linux, MacOs ad Windows versions.
- http://www.zpr.uni-koeln.de/~gato

Scalable Libraries for Graph Partitioning
- We are pursuing research in the area of new parallel methods for graph partitioning and incremental graph partitioning. Efficient methods for graph partitioning and incremental graph partitioning are important for parallelization of a large nu
- http://www.npac.syr.edu/NPAC1/PUB/ranka/part/part.html

Nauty
- A program for computing automorphism groups of graphs and digraphs. It can also produce a canonical labelling.
- http://cs.anu.edu.au/~bdm/nauty/