Atmosphir is a free video game / creation tool for Mac & PC. Design mode lets you create enormous 3D platforming levels filled with fun gameplay elements like power-ups and fireballs, while Play mode lets you explore through the thousands of diverse user-created challenges being uploaded every day.
Animation virtual studio.
"A virtual animation studio partnering with animators from around the world to create, high quality 3d, 2d and flash cartoon animations. Aniboom cultivates animated content by leveraging the web providing online animation opportunities such as animated competitions and free online animation software."