The open-source Laszlo platform consists of the LZX language and the Laszlo Presentation Server.
LZX is an XML and JavaScript description language similar in spirit to XUL and XAML. LZX enables a declarative, text-based development process that supports rapid prototyping and software development best practices.
The Laszlo Presentation Server (LPS) is a Java servlet that compiles LZX applications into executable binaries for targeted run-time environments. Laszlo currently targets the Flash Player. The LPS compiles LZX applications into SWF bytecode for the Flash Player, serves and caches these compiled applications to any Web browser enabled with Flash 5 or later, and proxies application requests for back-end XML data sources and web services.
A demo of Laszlo is here.
Also check out their uber-cool demo app LaszloDashboard.
