For the 2:40pm - the only game in town is Laszlo System's presentation: The Browser, The Portal, and the Desktop. If you haven't tried it yet, visit the OpenLaszlo site to see application samples created with the OpenLaszlo platform. It's FREE and open-source. The coolest feature is its ability to generate a Flash (version 6, 7, 8) edition or an Ajax edition. Under the hood - Flex and OpenLaszlo are very similar -- some even say that Flex was a copy-cat of Laszlo. Either way - we probably have OpenLaszlo to thank because it most certainly made Adobe open-source the Flex SDK and compiler sooner rather than later.
Now Laszlo System as I understand it is the commercial entity that is trying to make money by building solutions and consulting on the OpenLaszlo platform (somebody correct me if I'm wrong!). Laszlo is all over AjaxWorld, and they were demo'ing WebTop - a very attractive RIA desktop delivered via the web. WebOS anybody?
Open Laszlo is on my list of things to experiment with when I have time.
Since Adobe Flex 2 is free, why choose Open Laszlo? Here's what one of their engineers said....Open Laszlo deploys to Flash 6, 7, or 8 -- that's 98% of the browsers by Adobe's numbers. Flex 2 apparently requires Flash 9 (60%). So if you want to reach the largest audience without an install - Open Laszlo is the better choice (now). Also - if you are building widgets for mobile devices - Flash Lite provides Flash 7 support, not Flash 9. Which means - that once again - Open Laszlo would be the better choice (for now).
But if a Flash 9 installation is an acceptable installation requirement - then the difference seems to disappear since Flex 2 SDK is free, and Flash 9 is supposed to be noticeably faster.
If Open Laszlo had drag-and-drop interface like Flex Builder - then the scales would tip back to Open Laszlo...but their eclipse plug-in project has been archived.