What Does XML User Interface Language (XUL) Mean?
XML User Interface Language (XUL) is an interface markup language developed by Mozilla that enables developers to design applications that can run in both online and offline modes. XUL was introduced by Netscape in 1997 as part of what eventually became the Mozilla codebase.
Techopedia Explains XML User Interface Language (XUL)
XUL is based on the core existing web standards - CSS, DOM and JavaScript. XUL relies on Gecko implementations, and, hence, it is not interoperable with non-Gecko standards. XUL does not have any formal specification. Widgets running on the Mozilla platform can be developed using XUL and ported across different platforms. Components of XUL documents include:
