From John Rimell, Chief Architect, Cambridge University Press: jrimell@cambridge.org
The particular challenge we have right now is that we 4 sets of rooted tree/forest data structures (totalling up to 500,000 of nodes across say 20,000 trees per forest) and we need to test for isomorphism across the 4 sets but with a set of rules for what differences are allowable across the four sets. The data is the database of the Press' books. Having the solved the logic problem of testing for what is / isn't correct, there is also the challenge of providing a user interface/report to present the data errors (to enable an administrator to fix the errors), whilst not drowning them in all the information of what is correct... seeing the wood from the trees you could say.
This is a fine basis for a project propsal with a real end use and need if successful ...