A free ActionScript 3 library designed for developing 2D Flash games. It provides you with a fast, clean framework to prototype and develop your games in. This means that most of the dirty work (timestep, animation, input, and collision to name a few) is already coded for you and ready to go, giving you more time and energy to concentrate on the design and testing of your game.
I currently don't use any profiling tools and I'm aware I should do.
Some tools I'm aware of:
https://github.com/bengarney/PBLabsProfiler https://github.com/threerings/flofiler http://jpauclair.net/flashpreloadprofiler/
But there are more out there. What are other people using?