A good Library for testing whether a minors exists in a graph? I would like to know if there are any free graph libraries for testing whether a specific set of minors exists in a given graph?
NAUTY can be used as a library to help you build a hashtable for the entire poset of graph minors for small $n$.  The key would be the cannonial form given by NAUTY and the value would be a concatenation in sorted order of the cannonical forms of it's direct minors.