After almost a year of using PrimalScript for my Actionscript coding, I finally made the switch to FlashDevelop after the latest beta release.

It has everything I ever wanted in a script editor and even stuff that I didn't know I wanted until now.

The feature that I missed that finally made me convert was "Find in Files", a menu option to grep all your source for a string and display the results. But on top of that, the AS completion is really good, you can get the parameters of a method just by hovering over it, and my favourite feature "Go to declaration" is in there and working perfectly.

The user interface is really cool. With docking/popup panels for your project/workspace, files, and AS methods and properties (for easy navigation around your code), output and results from Flash or mtasc, and snippets. What is also pretty neat is that you can edit the settings xml if you want a certain feature to be in the right click menu for example (I liked having "Go to declaration" as the first menu option if I right click a method).

It integrates well with MTASC, and you can compile your movie in the flash IDE with a button press.

Its still a work in progress.. for example, you can only change your syntax highlighting colour preferences by editing the settings files, but the developers are really responsive to feature requests (and also very active, which is a plus).

If you haven't tried it out yet, or its been a while since you looked at it, check it out at:
http://www.flashdevelop.org/
Downloads are in the "Releases" forum.