What is the best IDE for actionscript3 development
Yeah by far the best IDE is eclipse with either fdt or flex builder installed (flex builder is just a packaged version of eclipse). The biggest problem with FlashDevelop is it's lack of debugging tools. If you get into eclipse, and teach yourself how to properly debug an application it can save you SOOO much time.
As for flex builder or fdt that's entirely up to you. The one big benefit fdt has is that it still supports AS2 development. FDT also has a lot of other nice features like code templating.
I have both but i mainly stick to flex builder for my flash work as for me i like the way i can use it for both flash and flex work and can easily switch between the two with minimum effort. If i had to do work in as2 again (god forbid) i'd definitely wouldn't heistate to switch back into the fdt environment.
flex builder because
- you can debug
- you can use the profiler you can real dig in to the player memory fix memory leak
- eclipse can do so much for you with tone of plug ins
- mylyn connect your data base bugs to your IDE and much more link svn commit to a task
- subeclipse plugin for SVN
FlashDevelop is a very good IDE for AS3 development. Haven't tried FDT, but tried Flexbuilder. I can say that it's much better for pure AS3 development (no mxml stuff). and it's free.
I have to expand euge1979's answer.
The Flex SDK (including framework, compiler, etc) is forked into a free Adobe owned Version and an open source version. Either way, you can compile SWFs for free.
The Flex Builder is NOT free. You have a 30 days trial.
A good thing to note is that FDT in the next version (from 3.1 to 3.2) will be able to handle mxml, thus making it equal to Flex Builder in terms of features. I really love some of the FDT features that makes common tasks easy - like formatting or creating functions, objects & etc.
Right now - stick with Flex Builder.
PS: Flex Builder is built upon Eclipse but it messes it all up. I experienced a lot of problems with FB as plugin and if I installed plugins into FB. And all the power vanished if I can't use it as plugin or install others into the eclipse.
My favorite environment right now is: Aptana Studio + FDT + PyDev + PHPDev