At MacWorld 2007, Adobe announced the release of its flagship developer IDE, FlexBuilder 2.0, for the OS X platform.

FlexBuilder has been available for Windows since mid-2006, and the OS X version offers substantially the same features. In explaining Flex's benefits to developers, Adobe evangelist James Ward noted in a 2006 Artima interview that:

Flex is a framework for creating all kinds of rich Internet applications targeting the Flash player. We sort of hijacked the browser and Flash Player to create applications that not only take advantage of, but also go beyond Flash’s traditional roles in multimedia.

Flash Player is deployed in 98% of the PCs world-wide, and new versions of Flash Player are adopted much faster than any other platform or browser... Over 80% of Flash Players are upgraded to the latest version within about 9 months of a new release.

FlexBuilder for OS X is available both as a standalone download or as an Eclipse plug-in.

In addition to this now widely available IDE, Adobe has made several moves in recent months to ensure that Flex becomes a popular developer tool for Web-based applications on both the client and the server. Chief among these are the open-source release of the Flash runtime used to execute Flex code (see Artima's interview with Dan Smith about the Mozilla-supported Tamarin project). Since Flex is Adobe's branded version of EcmaScript 4, the next-generation JavaScript, it is positioned by Adobe as a way for developers to write future-proof Ajax applications.

With that momentum behind Flex, do you think it's important for Java developers to learn Flex?