Current state of Rails CMSs

I've been using Rails for many years, but it's been primarily for
building custom applications and hosting small sites with less than ten
pages. I'm interested in learning a CMS to start building more
content-heavy sites.

The last time I looked at Rails CMSs was years ago. Does Radiant still
have the largest developer community? How does it compare to PHP-based
CMSs like Wordpress?

Does anyone use Rails for custom app development but Wordpress as a
general site hosting solution? I'm hesitant to devote a lot of time to
learning and extending a Rails CMS given that Wordpress is so ubiquitous
and has such a large developer community behind it.

http://ruby-toolbox.com/categories/content_management_systems.html

Looks like Radiant is still in the lead, but some of the runners up also look promising, might check them out and see if they fit your needs better.

The second one on the list, Browser CMS has a conference presentation you can watch to get a better feel http://aac2009.confreaks.com/07-feb-2009-10-00-browsercms-patrick-peak-and-paul-barry.html

The third one on the list, Refinery CMS, has a short video overview. Their site is pretty slick, and presumably uses their CMS.

Quite a few have example sites, but some aren’t Rails, so if that is important to you, be sure to look for it.

check out
http://railsbased.org/

You might want to check out Adva:

http://adva-cms.org/
http://github.com/svenfuchs/adva_cms

It's very easy to use/install and because it's based on Rails engines,
it can live
with your existing Rails application

Good luck