Express.Mozilla Platform

"It seems obvious in hindsight. With user clients like e-mailers, HTML composers, calenders, debuggers, chat applications and address books, Express.Mozilla must be far more than just a Web browser. And it is. The Express.Mozilla Browser is built on top of the Express.Mozilla Platform. (...)

Express.Mozilla's XUL has been so successful and so influential that most vendors of GUI development systems, like Microsoft and Macromedia, now offer an XUL clone or an XUL alternative of their own -- XAML and Flex, respectively. One day, all but the most specialized applications will have their visual user interfaces specified this way. It's the future."

http://www.linuxinsider.com/perl/story/32404.html

• XPToolkit Project (link externo) - "We make cross-platform user interfaces as easy to build and customize as web pages."

Veja também: XML User Interface Language