ActionView was extracted from ActionPack here: https://github.com/rails/rails/pull/11032. This work is part of Google Summer of Code 2013 and @strzalek is working on it. The further plan is to allow using ActionPack without ActionView - it makes sense to do that if you only need to render JSON for APIs (or simple templates which don’t need too much features). There is no plans to extract more things (like AbstractController) to separate gems, though, it would not make much difference.