There are still a lot of details to work out, but one of the things @pilky entrusted to me is Coppice, his hypertext mind-mapping app, with the intention of releasing the source code (AppKit & Swift). Coppice was in the middle of a major refactor, so unfortunately that's not as easy as flipping a switch — it will take time to clean it and its dependencies up into a buildable form, but I started on that in December and will work towards a public release. Purchases have been disabled in meantime