Many of us have discovered the benefits of using Flex for rich client side applications in conjunction with enterprise Java on the server side. The Flex/Java EE combination brings the best of both worlds to the developer seeking rich clients with robust enterprise strength back-ends.
While Flex and Enterprise Java go very well together, Flex is also used with a myriad of other languages. Some advertised efforts related to various languages and frameworks making special effort to work even better with Flex include PHP (Zend - "Zend to Collaborate with Adobe", 16 September 2008), Ruboss (22 May 2008), Ruby on Rails (Flexible Rails), Python, C++, and .NET ("Adobe Flex Reaches Out to .NET Developers", 17 November 2008).
In the Flex+Java world alone, there are many alternatives as well. While HTTPService and WebService make Flex useful with virtually any modern language, Flex (either directly or via its community) has a wide range of Java-specific goodies as well. These include BlazeDS (including support for Spring+Flex, JMS, and Java object remoting), and GraniteDS (specific support for Enterprise JavaBeans 3, the Spring Framework, Seam, and Guice).
Now, we have an announcement that SpringSource will be collaborating with Adobe to deliver Spring BlazeDS Integration. SpringSource will also be releasing an adapter for LiveCycle Data Services ES. With the established pervasiveness of the Spring Framework in the Java EE community and the rapidly growing popularity of Flex in the Java EE community, this announcement was really not much of a surprise and makes a lot of sense. Other articles covering this announcement can be found here, here (extra details), here, here, here (details on what Spring BlazeDS Integration offers above today's Flex+Spring options), and here.
Flex continues to be used with an ever increasing variety of back-end technologies. However, for those of us who still primarily develop our enterprise applications with Java EE and Spring, today's announcement is very good news.