http://www.xmlportal.net

Well, the first one since I'm working on that project. Open sourced by Activitats Organitzatives and hosted at java.net. Take a look.

http://java.sun.com

Needless saying what you'll find there. Pure Java by their creators, Sun Microsystems.

http://www.netbeans.org

My favorite Java IDE, despite there exist others also opensourced, like Eclipse from IBM, my choice is definitely NetBeans.

http://www.opensuse.org

A great Linux distribution. Free and with a lot of documentation and support. Novell is there.