How is a layout engine like Gecko different from a Web browser?
Gecko provides the foundation needed to display content on the screen, including a layout engine and a complementary set of browser components. However, Gecko does not package all of these components alongside other interface modules in a coherent, user-friendly application (including menus, toolbars, etc.), such as Firefox. mozilla.org assembles the necessary components into its applications, such as Firefox, Thunderbird, SeaMonkey, Camino, which are available for free download from mozilla.org. Netscape released its own version of the browser branded as Netscape Navigator. Other companies release their own software and hardware products that use Gecko. See XULRunner Hall of Fame for a partial list of application that use Gecko via XULRunner. Third parties such as ISVs and hardware vendors will pick and choose the components they want to use in their applications or hardware devices. Certain browser components are not provided as part of Gecko, such as bookmarks, history, address book
