Here we have a post by @rhyolight about NuPIC encoders. However, there may be some encoders for NuPIC which were created by some community member and that are not (yet) part of NuPIC. So, the purpose of this post (which should be made a wiki by an admin, so that to allow everyone to add links to new encoders) is to list all such encoders (so as to serve as a reference).
A first idea to organize this post would be to have a section (and possibly subsections) for each domain.