I think Subauthz is finally ready to be used. The feature-set is nearly completed, and I think it’s quite enough to manage Subversion’s current authentication features for one or multiple repositories.
I’m trying to get the time to write a quick tutorial on usage, though it must be quite straightforwarded. Take a look at the installation instructions here.
You can test it in http://subauthz.omelas.net, or you can download it from the repository.