Locomotive is a simple but powerful CMS based on liquid templates and mongodb database. At my company ("NoCoffee":http://www.nocoffee.fr), we use it for our clients when they request a simple website.
If we have to give only 5 main features to describe our application, there will be:
We already developed a fully functional prototype in Rails 2.3.2 with both active record / mongomapper and it worked quite well. We are even using it for some client websites.
Now, our goal is to port our prototype to Rails 3 and migrate from mongomapper to mongoid. Besides, we put a lot of efforts to make it as robust as we can by writing better specs than we wrote for the prototype at first.
If you wish to upgrade your locomotive install from an older version to the current 1.0.0rc1 then "please refer to the upgrade guide":http://www.locomotivecms.com/support/howto/upgrade
"Rodrigo Alvarez":http://blog.codecaster.es/ for his plugin named Congo which gave us a good starting point and for his availability for (very late) tech discussions.