flixel
flixel is a free Actionscript (Flash) library
Flixel is a free, open-source game development library written in ActionScript 3 originally for Flash, created by Adam “Atomic” Saltsman. It provides a lightweight yet powerful base framework to build 2D games: handling rendering, input, collisions, tilemaps, particles, cameras, etc. It was designed to be easy to learn and extend, useful both for simple arcade style games and more elaborate ones. It has been used for many indie / Flash games (including commercial and contest-nominated ones...