You can clone with
These are all Java based CMS that are using JCR, specifically Jackrabbit. This means they might serve as an inspiration in how content is structured in the repository. But also form the point of view of the UI.
Also since they all use Jackrabbit, once they will upgrade to 2.3.6 or later, we should in theory be able to read their data. So this might enable setups where these CMS are used for data entry and our tool chain is used to present the data in the frontend.
http://www.pimcore.org/ is also a project that is worth trying it. UI is using extJs (which license does not fit to be used in symfony cmf if I understand it correctly). Not sure if it uses JSR but the nature of content management looks similar. I tried it maybe a year ago just to play and it impressed me much.
we have some preliminary tests done with Magnolia .. we will soon publish our findings.
the hackday with magnolia was successful. read more in the blog post: http://blog.liip.ch/archive/2012/05/08/php-talking-to-magnolia-cms.html
now who is up to try with adobe crx? or hippoCMS?