OpenLaszlo - A Really Cool Flash UI API
OpenLaszlo is an open source platform for the development and delivery of rich Internet applications. It is released under the Open Source Initiative-certified Common Public License.
Especially 4.2, it is the recommended platform for all application development in the SWF8, SWF9, and DHTML runtimes. The major new feature in OpenLaszlo 4.2 is the introduction of the SWF9 runtime, which can offer significant performance gains.