Rehashing an older post: http://stackoverflow.com/questions/1570070/jquery-vs-flex-choosing-a-platform-for-saas We are preparing to develop an application that is exceptionally dynamic and interactive. It's particularly heavy on the graphics side. We are 85% convinced that Adobe Flash built atop Flex is the right path to take, however Cappuccino is quite nice and seems as though it may be able to nearly fit the bill. The only pause we have right now is portability for the iPhone. With the lack of blessings from Apple we will most certainly have to create a 2nd interface for the iPhone for the site, however... Having two interfaces may not be bad as it will likely have to be custom anyway to take advantage of the differences that it affords. Any further thoughts or reevaluations of points enumerated in the noted article? Further, Flex 4 adds a lot of strength to the position mentioned previously regarding UI development. Fx4 is very nice vs Fx3 and shaves 90% from the development time when coupled with Flash Catalyst, which is not really always fully appropriate, but with some round trip tricks it seems as though it can cut through things rather well... Please do advise and many thanks.