OpenLaszlo is an open source development platform for web applications. It's main target today is generating macromedia flash files (swf)and AJAX/DHTML for use on web pages and sites.
OpenLaszlo is script based with it's own LZX programming language - and eventhough it does not provide a wysiwyg user interface it a still simple to use and applications are easy to build.
For building rich internet applications
OpenLaszlo is a great tool. And recently OpenLaszlo and SUN made a joint announcement to make OpenLaszlo available on Java micro edition (J2ME), which includes mobilephones and set-top boxes.
OpenLaszlo is the only rich internet platform that lets you write once and compile to both flash and DHTML. It's easy to get started with OpenLaszlo.