Copyright 2015 GarageGames LLC
Based on Scratch from the MIT Media Laboratory under the GPL 2 license.
Game Stack is the companion application to the DevPro Game Design & Programming Curriculum for High School and Higher Ed. You may get started for free at the GG|Interactive web site.
To build Game Stack you will need the Apache Flex SDK 4.11, Flash Player 11.6, Adobe AIR 3.6, and Flash Builder 4.7. The Apache Foundation has an installer that makes it easy to select the correct version of Flex to install. Flash Builder is available from Adobe.