Route is an experiment to see what it would look like if Rails controllers specified how to reach themselves, rather than having an omniscient routes.rb file.
It contains a simple Rails project which illustrates a proof of concept in github.com/codeodor/route/blob/master/app/controllers/courses_controller.rb.
The code behind the proof of concept is in a gem which you'll find here: github.com/codeodor/route/tree/master/vendor/gems/route
It hooks into Rails with the railtie: github.com/codeodor/route/blob/master/vendor/gems/route/lib/route/railtie.rb and it does the work of sending the calls to specify routes in github.com/codeodor/route/blob/master/vendor/gems/route/lib/route/route.rb
See my blog post for discussion of why having Rails controllers specify their own routes could be a good (or bad) idea.