XUL stands for XML User Interface Language. It is an XML markup language that allows for GUI-based application creation using the Gecko and Goanna layout engines. In turn, these layout engines provide several technologies used to build applications. Pale Moon and Waterfox are just two applications built using XUL and the Gecko/Goanna layout engine. XUL makes it easy to build your own stand-alone applications through the use of XPCOM, JavaScript, HTML and CSS. This book is intended to be a quick start-style resource to give you the basics of creating a XUL GUI along with how to make that GUI actually do something using JavaScript and XPCOM. This 7th Edition incorporates information on using Waterfox and Pale Moon as the basis for your own stand-alone applications. Expanded information on notification boxes, popups and panels is also included in his new edition.