CMS exposing data as a RESTful API
content-management-system
Solution
You should take a look at http://osmek.com/ or http://expressionengine.com/ with the Export it plugin. It allows for channels to be pulled using a REST API.
I have been on a crusade to separate the CMS from the front-end of all of my projects and I have used ExpressionEngine in the past and really dig it. Another plugin that you may like with EE is Playa,it allows for relational data models.
Good luck
Problem
Can you recommend a CMS that exposes the entire stored content through some kind of API (HTTP, XML-RPC, web service)? I want to use it only for creating/editing content, and the content will be then retrieved from another site. For instance, Wordpress has the type of API I am looking for, but unfortunately it lacks some of the functionality I need (hierarchically organized articles and media, article and image ordering, image galleries...).