I’m moving from Flex back to AS3 only for my next contract. So I’m going to experiment with some alternatives to Flash Builder.
FDT 4 from Powerflasher.com is a commercial alternative. Being an eclipse editor, the features should be familiar. Downloading and starting my trial period with it. The cost for the entry level version is cheaper than Flash Builder. The mid-level is definitely not. And the high-end version with profiler is similar to the Flash Builder 4.5 Premium version.
Sublime is a text editor for code. The beta supports AS3. $60.
Previous tools I have used: FlashDevelop.
Off to write some code!
