Isn't bootstrap a front-end theme toolkit? Why does it need to be "ported" to Rails? Can't you just use whatever CSS + ERB templates you want to with Rails?
Totally right, it's a front-end theme toolkit, but relies on many dependencies to be compiled (check the gemspec file).
Same question goes for the `twitter-bootstrap-rails` gem and a few others.
Saves a lot of time and hassle to add it as a gem and forget about it!