Our CMS, Forge (http://factore.ca/forge-cms) is a semi-open source (in that you're free to use it for whatever you want but we don't have a community built up for it yet) Ruby on Rails CMS that focuses on rapid application development. It's VERY opinionated (moreso than Rails) but it lets you get things done really quickly and mostly stays out of your way on the front-end. Shoot me a message if you're interested in checking it out.