The current development version is version 1.3. It's officially still in alpha but the core and most modules are pretty stable. The new TextRange and Highlighter modules are still in active development and as such are more unstable.
There is now an official Rangy 1.3 package for Bower, called
Rangy now has AMD support.
There is a Rangy module on NPM called
rangy. It doesn't do anything useful in Node but you can do Browserify stuff with it.