I've collected all open source CMS based on rails 3.x.

Rails CMS/Wiki/Forum

This is a very simple but feature rich CMS framework. It is good startpoint for a new rails project what will be wiki, Forum or CMS

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Casein CMS

This is a very minimal and lightweight CMS. Only users table created on rak db:migrate. It is a good start point for any content based application. This application scaffolding your rails app with a very beauty user interface.

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ADVA CMS2

This CMS is not running on ruby 1.9.2. So I can't try out it.

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Refinery CMS

This CMS is work perfectly out of the box. It useable by a non programmer user too.

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Radiant CMS

This is a very old CMS with still active development team. I think this is a usable CMS for a programmer.

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Typo weblog engine

This is a blog engine, but you can use as CMS.

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Update (2011-07-18):

Locomotive CMS

A great NoSQL CMS. It uses MongoDB. I'm very happy to see this new CMS.

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