This release builds on top of the Apache Felix OSGi runtime, offers great extensibility, support for Rails and Grails, developer features (fast startup, retain sessions across redeploys, NetBeans and Eclipse tooling, ...), an embedded API, Comet support, a brand new IPS-based update center, RESTful web services, a preview of several Java EE 6 features, and much more. Check out the press release, it also mentions a few partners building on top of GlassFish v3 Prelude. Read more and download the bits at http://blogs.sun.com/theaquarium/entry/glassfish_v3_prelude_launching_today .

GF v3 Prelude basically fits in where Tomcat would in your development stack. It's not an EJB container, rather it's a Servlet container. I do not know, but I believe the Prelude will continue to exist, even after GF v3 comes out as a full boat EJB 3.1/JEE 6 container, particularly with the different Profiles. So, what that means is that anyone who has not been considering Glassfish as a Tomcat replacement due to its size and extra features, may want to take a good look at GF v3 prelude. I think it's can be a confident choice in the future for those looking at a pure Servlet engine.

I can't figure out what it is. Sounds like a container of buzzwords.