This list has many of the plugins I already use, and there are more that I haven’t looked at yet. I’ll give them a shot in due time, but it’s a good reference.
FlexBuilder may have its ups and downs but it still remains my pick for best AS3/MXML editor on the market (with TextMate not far behind). Part of the beauty of FlexBuilder is that it’s built on the Eclipse SDK, one of the most versatile and powerful IDEs available, which is not only free and open source, but boasts a wealth of third party plug-ins
for every kind of (mostly Java) development. This article will take a
look at some must-have plug-ins for doing Flex development as well as
some tips for tricking out your development process.