I'm starting a new Java project which will require a RESTful API. It will be a SaaS business application serving mobile clients.

I have developed one project with Java EE 6, but I'm not very familiar with the ecosystem, since most of my experience is on the Microsoft platform.

Which would be a sensible choice for a JAX-RS implementation for a new project such as described?

Judging by Wikipedia's list, main contenders seem to be Jersey, Apache CXF, RESTeasy and Restlet. But the Comparison of JAX-RS Implementations cited on Wikipedia is from 2008.

My first impressings from their respective homepages is that:

• CXF aims to be a very comprehensive solution (reminds me of WCF in the Microsoft space), which makes me think it can be more complex to understand, setup and debug than what I need;
• Jersey is the reference implementation and might be a good choice, but it's legacy from Sun and I'm not sure how Oracle is treating it (announcements page doesn't work and last commit notice is from 4 months ago);
• RESTeasy is from JBoss and probably a solid option, though I'm not sure about learning curve;
• Restlet seems to be popular but has a lot of history, I'm not sure how up-to-date it is in the Java EE 6 world or if it carries a heavy J2EE mindset (like lots of XML configuration).

What would be the merits of each of these alternatives? What about learning curve? Feature support? Tooling (e.g. NetBeans or Eclipse wizards)? What about ease of debugging and also deployment? Is any of these project more up-to-date than the others? How stable are them?