Akamaru is a simple, but fun, physics engine prototype. It's named after the super awesome ninja dog, Akamaru, from the Naruto anime and based on the article Advanced Character Physics by Thomas Jakobsen on Verlet integration. It's not really clear if Akamaru is useful at all, but it's definitely fun. Screenshots really don't do it justice, it's all about the animation; here's a couple anyway: Aka