XULRunner is a free utility designed for developers looking to create standalone desktop applications using the Mozilla platform. This software enables the development of applications utilizing the XML User Interface Language (XUL), providing a framework that allows for a rich user interface and seamless integration with web technologies. Although it has been discontinued, XULRunner remains a relevant tool for those interested in leveraging Mozilla's technology for application development.

As part of the Mozilla ecosystem, XULRunner supports various features that enhance application functionality and performance. Developers can utilize its capabilities to build applications that can run independently of web browsers, making it a versatile option for creating user-friendly interfaces. Despite its discontinued status, XULRunner's legacy continues to influence desktop application development practices.