At blist, I use Flex Builder a lot. It’s essentially a plugin for Eclipse, the IDE that grew out of the Java world but now seems to do almost as much as emacs via plugins. While you can use the free Flex SDK to build Flex applications, there’s really no decent alternative to Flex Builder for rich debugging support or profiling. Without that, I’d probably switch to using a text e ditor – it’s just too buggy to be my primary editor. Here’s a few examples:

Flex Builder supports incremental background compilation of your project. (There are also ways to accomplish this from the command line, but that’s another story.) This means that you can simply save your work as you go, and it’ll happily go off in the background and build your project for you, and only need to rebuild the parts of your application that have changed. This is great if it worked – but the background support is shoddy. If I have a few different files open for edit and hit Cmd-Shift-S (Save all), all the saves aren’t atomic – the first file will save, Flex Builder notices the file was saved, and starts a build. The build finishes, some more files get saved, and then the build starts over again. Even worse, the build process isn’t always in the background – I got enough hangs after saving while it started the background compilation that I turned it off. Instead, I just save when I want and hit Cmd-B to build the project when I want to actually run it.

But even that doesn’t work properly. If I hit Cmd-S, Cmd-B to save and build, the save operation often won’t have registered before the build operation, so the build process doesn’t start. As a developer, rely on muscle memory for keyboard shortcuts, but it’s really getting on my nerves that a common key sequence (save and build) can’t even work consistently.