I recently had the opportunity to explore the Adobe Flex framework and although it's really just Flash on "component" steroids, I came away impressed. Novices and experts alike can build rich web applications with ease in just a few lines of Flex code. What really had me impressed was the fact that Adobe opened up the source to the free SDK, and based their design of the Flexbuilder application on the widely popular Eclipse IDE. The one downside is that the components themselves aren't easily customizable, so more advanced users who want to create visually pleasing applications will have to devote a little "eye candy" time before deploying their code.

Follow this link to the Adobe website if you want to learn more about Flex. Also check out the Vector Magic website, which is quite possibly the most amazing example of a Flex application you will come across today.