Ajax and Flex share a lot of Web 2.0 themes. They both create engaging experiences with compelling user interfaces. They share the same standards: HTTP, XML, ECMAScript.
Andrew from Adobe says Ajax is limited by the browser environment. There aren’t many UI components. Developers must test across lots of browser/platform combinations.
Flex gets around that by circumventing the browser and targeting the Flash player. Flash has become a real platform. It’s still used as an expressive medium but also more and more for video. It’s also good for end to end communications: training, meetings, etc.
Flex is a framework, unlike the Flash authoring tool which is fine for movies and timeline-based stuff. Flex is for developers. You use MXML, ActionScript, CSS and a library of classes (UI containers, controls, drag’n’drop, etc.).
Here’s a live demo of something he cooked up this morning using the Flickr API.
You can view source!
After demoing a few pure Flash examples, he brings up Measure Map which mixes Flash and Ajax.
The Flex SDK is being made available completely free of charge. The Enterprise Services server is free for a limited number of uses; enough for small businesses. The Flex Builder IDE will cost less than $1000.
Ajax may be enough for you. Flex is an alternative if you are frustrated by the browser.
Visit Adobe for downloads.