A Flash Molehill (Stage3D) GPU accelerated 2D game engine
Create symmetric sprites: browse, save to PC, or store online
A free ActionScript 3 library designed for developing 2D Flash games
Zoë is an open source tool for generating spritesheet images
Hungry Hero is an open source Flash game built on Starling Framework.
Symmetric Sprite Editor
FlashDevelop plugin to make assets library swc and swf.
StarlingPunk is a framework built on top the Starling library
Set of actionscript tools to export animations and graphic assets
flixel is a free Actionscript (Flash) library