XUL is part of the Mozilla project. It allows you to specify user interface (UI) in a cross-platform, and attach scripts to events. XUL is used by Mozilla's web browser to control its UI, and can strip the outer layer. XUL is based on XML, which uses JavaScript to handle events. With XUL, you can create a unified graphical user interface (GUI) across any platform, as long as Mozilla can be used on these platforms. The UI created using XUL will retain its appearance and operation experience on the main platform.
