GNOME panel is, well, the panel in GNOME. You know, the bar you see at the top and at the bottom of your desktop, with menus and lots of applets on it. That's it. That's the panel.

This is the "Toujours plus utiles, plus forts, plus beaux" release: the menu bar now uses a new layout. The menus should now make every user happy. Also, developers of applets that need to get focus should look at the new panel_applet_request_focus() API.