Base Eclipse does not support any facets of J2EE development. Eclipse in fact is only a framework, and it requires plug-ins to do anything. The Eclipse team delivers two basic plug-ins: the JDT (
Java Development Tooling) which allows you to create J2SE applications, and the PDT (Plug-in Development Tooling) which allows you to create your own plug-ins.
The primary Open Source J2EE plug-in is Lomboz. I am not as familiar with that, since I use IBM's WebSphere extensions, which are not free (unless you have an IBM iSeries machine). I love the WebSphere components because they allow you to actually run an application server test environment right on your PC and so you can debug your application without even having to deploy it to the application server.
As I said, though, the WebSphere components are commercial, and if you're worried about memory requirements for Eclipse, the test environment takes even more.
Joe