If I had to start our project all over again, we would use
AJAX instead of flex, for the simple reason that we could run
ubuntu on our machines instead of windows. The developers all want
to run linux.... The only thing keeping me on windows is adobe
apps. If I could drop adobe apps I could drop windows....
Have you tried installing flex builder as an eclipse plugin?
I haven't tried to get flex builder on my ubuntu install, but since
flex builder is available as an eclipse plugin; in theory, you
could install it on any platform that supports java.