First, create a script that starts only what you want, and put it in an appropriate location like
/usr/local/bin. For instance, this script starts the Metacity window manager (you'll experience some difficulties if you don't run at least a window manager) and Eclipse. (There are some fancier things you can do, for instance in this example I showed how to restart the program if it is exited.)
Then, make it executable by running
chmod +x /usr/local/bin/eclipse-kiosk.sh. Now, create a desktop file for it in
Eclipse Kiosk will appear in the GDM sessions menu and GDM can be configured to log in using it however you want.