Scratch is developed by the Lifelong Kindergarten Group at the MIT Media Lab, with financial support from the National Science Foundation, Microsoft, Intel Foundation, MacArthur Foundation, Google, Iomega and MIT Media Lab research consortia.
Scratch is a programming language that makes it easy to create your own interactive stories, animations, games, music, and art -- and share your creations on the web.
A collection of projects for Let's Get Physical with Scratch: Sensors, Robots & Consoles BYOD session at #ISTE13. More @ http://techkim.wikispaces.com/cs4all.
Learn how to incorporate external sensors and input devices into your Scratch projects. We'll examine a variety of projects, utilizing different input devices, that participants can remix and share.
Gimp is a pretty popular free paint tool. This artist creates brushes for Gimp and Photoshop. There are dragon, planets, butterflies, plants etc... It's very very useful for creating backgrounds and sprites. All brushes are free and no-credit (read the ToS though).
The STEM Video Game Challenge is running through March. Participants can register now and utilize a number of free game design tools to create their own game or submit a design document with an idea for a new game. The contest is open to US residents in grades 6 through 12.
This is a great post about the history of Visual Programming Languages. The author also has produced an infographic about different visual programming languages like Scratch, Alice, Kodu Game Lab, Stencyl, etc. and their special abilities.
For those interested in programming and game development, this channel has videos on creating a game from scratch using Java. There are many similarities with GML; even if you are not interested in programming with Java, you can learn a lot of things useful in GM too.