GraphCanon is a C++ library with an algorithm framework for graph canonicalization, graph isomorphism, and computation of automorphism groups of graphs. The package additionally contains a program graph-canon, which makes many variations of the core algorithm available from the command line. The program also facilitates extraction of additional data from the algorithm run, e.g., visualization data for the GraphCanon Visualizer.
The library was initially written as part of the paper A Generic Framework for Engineering Graph Canonization Algorithms [DOI | TR].
The documentation can be found at here. See either here for installation instructions, or in the file doc/source/installation.rst.