Do you mean CRM (customer relationship management), or CMS (content management system)? I only ask because Spina is a CMS.
If you do indeed mean CMS, can I ask, why does it have to be Ruby-based? Are you looking to build something more dynamic, and if so, to what level of dynamicism (not a word, don't care) do you need?
Depending on your requirements, maybe one of the platforms I've outlined here might be handy:
If you do need something more than just a CMS, however, look at Comfortable Mexican Sofa. I've not used it myself, but I've heard about it.