So I don't get it. The Guide is freewere, and it is clear that the developer has no intention of continuing development. So wouldn't it make sense to just release the source code so someone can pick it up?
IMO the source code of any abandoned piece of software, free or commercial, should be made publicly available, so that other people don't need to waste valuable life time re-inventing the wheel. This is my opinion as a developer. If nobody is making money from the software, what good is it to keep it locked from the world?