Which is a nice desktop Linux distribution - with a great GUI to match - , that's also free, to learn new features of J2EE?

Ubuntu or Debian, with the latter requiring some extra work to configure. Or Solaris Express Developer Edition - but that's UNIX, not Linuix - and it will take some tweaks to get rid of a few bugs affecting Tomcat and Java Applications Server.

Does Ubuntu work well with JBoss? I want to learn new features of JSP. I'm an ASP.NET 2.0 developer wanting to know if new JSP is as object-oriented as ASP.NET or if it's just script-based like classic ASP. If JSP is object-oriented, I would like to run a JSP website in parallel to my ASP.NET site.

So, this may be not the right forum, but which would be a nice open source and free J2EE server to do this on?

Thanks.

Frankly, the distribution is hardly relevant. JSP can be coded in Eclipse or Netbeans and both can be installed on any distribution, be it Ubuntu, Debian, Suse, Fedora or any other. Although Fedora is generally a good choice, it may be less attractive to anyone who is new to java and JSP because it still doesn't come bundled with Sun's jdk; you would have to fetch it and set it up yourself. That's not extremely difficult but it's just easier on the other ones, where it can be installed with a few simple mouse-clicks.

I personally don't use Jboss but it can be downloaded together with Netbeans (check out the Netbeans site). Tomcat is available on most Linux distributions and Sun Java Application Server / Glassfish can be downloaded either from Sun or from the Netbeans site.

By the way, what do you mean by new JSP? JSP has always been object-oriented. You may not notice at first, though, because most tutorials start from simple scripts.

Once you're familiar with the basics, you should also look into frameworks like Spring, Struts, Hibernate etc . Those will save tremendous amounts of coding.

Note: I recommend 32 bit Linux even for 64 bit pcs; some java components haven't been implemented in 64 bit yet.