Earlier this week, Adobe released Flash Builder 4, the successor to Flex Builder 3. The new version includes a ground-up overhaul of the Flex SDK component set and significant enhancements to both the ActionScript development environment and the MXML design environment. Anyone using Flex Builder 3 today should definitely upgrade. The improvements in Flash Builder 4 are extensive and wide-ranging, and well worth the investment.
In particular, the rewritten component set introduced by Flex SDK 4.0 is very welcome, and demonstrates that Adobe has a deep commitment to Flash-platform application development. Much as ActionScript 3.0 transformed Flash programming when it replaced ActionScript 2.0, Flex 4.0 is a rebirth of the Flex framework. Adobe clearly learned much from Flex 1.0, 2.0, and 3.0, and has responded with a coherent, evolved architecture that provides a solid foundation for a long-term, stable growth strategy. Flex 4 redefines Flash application-development with a new paradigm that's here to stay.
Developers new to the Flex framework should proceed directly to version 4.0, and skip 3.0. Developers already using Flex 3.0 should migrate to 4.0 when possible, but need not fear that 3.0 has been abandoned; Adobe will continue to maintain 3.0 while the community transitions to 4.0. Flash-authoring-tool users who write timeline scripts and don't use object oriented programming can skip Flash Builder 4.0 altogether, but might want to give Flash Catalyst a look.
Flash Builder 4.0 and the Flex 4 SDK, however, still have room to grow--despite all the good work done and advancements made in the latest release.
The Flex 4 SDK, for example, does not include all the components that were available in the Flex 3 SDK. Notably absent are DataGrid, Tree, and DateChooser. Full component parity is planned for the future (Flex 5, hopefully), but until then developers must in some cases mix older Flex 3 components into their Flex 4 applications. Not ideal, but a reasonable price to pay for the benefit of working with the new Flex 4 architecture today.
Likewise, Flash Builder 4's code editor is still missing some of the trademark "coding comforts" available in FDT, a competing ActionScript IDE. For example, FDT's impressive range of "Quick Fixes" are sorely missed in Flash Builder 4. A few aspects of Flash Builder could also use more polish. For example, Flash Builder's "Rename" and "Find references" are a little flaky, even in the 4.0 release build. A couple times a week, "Rename" and "Find references" seem to miss a few references in my 10,000-line code base. I've become accustomed to hunting down oversights via compiler errors and "Find in Files", which is an unpleasant feeling. I also really feel that Flash Builder needs easier Flash Player selection, and needs to finally rid itself of debugger-connection failures that cause hard-to-diagnose messages such as "Flash Builder cannot locate the required debugger version of Flash Player." (Vote for improvements here.)
Nevertheless, Flash Builder 4.0 is a very large step in the right direction. It is unquestionably superior to Flex Builder 3.0, and lays an important foundation for the work that remains to be done in Flash Builder 5.0 and 6.0. Judging by the dedication and professionalism I've seen demonstrated by Flash Builder's engineering and product teams, the coming versions are bound to be impressive.
For more info on Flash Builder 4, see:
Students and faculty of academic institutions can get a free copy of Flash Builder 4.0 here:
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The premium version and standard version of Flash Builder share most features in common, but premium comes with a memory and performance profiler, and a network monitor. For more details on the difference between standard and premium, see the version comparison chart.