FlexBuilder is a lovely piece of work, no denying it. But have you every used the Eclipse Java environement? Now that's a lovely piece of work. It's what all IDE's should aspire to, FlexBuilder's on the way but it's not quite there yet.
The Flex Tools project aims to give FlexBuilder (and in turn, you, the developer) a helping hand in increasing your productivity.
At one point, Open Hub analyzed source code for this project based on code location(s) available at that time. Since then, the code locations have been removed.