IBM has released an IDE that can be used for both Java and C++, even at the same time, and includes debug, team development capabilities via a GUI interface to CVS, and other features. There are two versions: one for WinXX and one for Linux. The Linux version comes in two flavors: motif and GTK. They look and feel identical on both platforms. New features/capabilities are added by installing plugins. Eclipse itself can be used to create new plugins for itself. So far, I like what I see. I found one problem in the Linux version... the tutorial/help files opened up on the tree side but not on the text side, so I used the online tutorials. (One hint: to add an existing project first make a new project and then use the IMPORT feature to import the existing project under the new project. When you do that you will see that not only is the project imported in, but the entire JDK tree. When you hoover your mouse over an object(class, method, property) a ballon appears telling you where that object was derived from, and also allows you to jumpt there. Pretty standard stuff.
It is under their version of the GPL, which adds extra clauses insuring that violations of patents and trademarks don't climb back up the user tree to IBM.
Find it at http://www.eclipse.org
JLK