Today marks the official(ish) release of GlassFish v3.  v3 is the product of years of hard work in what is, in some ways, a rewrite of v2.  Built on top of OSGi, v3 offers a modularity and extensibility leap over v2.  It's also the first to fully support the JEE 6 specification.  I've been a spring guy for a long time now but honestly (and employer imposed bias aside)  JEE 6 makes a compelling case for skipping spring altogether.  At least for my uses. GlassFish v3 and JEE 6 offers a number of profiles so you can install as much or as little as you'd like.  Using the web profile gives you everything you need to run many web apps.  You can add additional features via the updatecenter as you need them often without needing to restart the server.  If you're a v2 user most of that should be very familiar to you already.  Borrowing from Eduardo's blog entry:

Key links available now:

• GlassFish v3 Main Product Page • JavaEE 6 Hub • JavaEE 6 Downloads (multiple bundles) • Java EE 6 Feature Article (also see Overview White Paper).

You can read more here.  You can also find all the GlassFish v3 related blogs on blogs.sun.com (at least those tagged as such) here.  I'm really quite excited about this release but at the risk of sounding too press releasey about it all, I'll leave the gushing to others.  You can check it for yourself by downloading it.

Download it.  Kick the tires.  Take it for a spin.  I think you're going to like what you find.  Especially if you haven't given glassfish a look in some time.  This is truly a different creature.