This shows the Modern theme when a 0.9.4 nightly build is launched. The Address Book sidebar panel is shown. This is the browser with nearly all the chrome hidden or closed, showing how much room can be saved. Mozilla's Address Book, showing addresses collected by the mail client. Mail Compose window, showing the autocomplete dropdown list.
Composer looks quite polished using the Modern theme.
Mozilla's Preferences window. Note the extensive range of preferences available. Chatzilla is Mozilla's IRC client. Mozillazine's old screenshots page and sidebar. Toy Factory theme.