W. Kuperberg asked a question about plane geometry, which invites contributions to solving a research problem which he has worked on.
Given that we're a questions and answers platform, I'm not positive than MathOverflow is the optimal place for such a question: but the project he is proposing seems worthwhile, and it seems a fairly decent polymath-like request as such things go. Can this and similar questions be usefully migrated to a polymath-suitable platform, in which people can post little comments, share knowledge, and make progress together? E.g. to some sort of linked blog?
Any ideas? For this and for similar questions, which do come up from time to time.