OpenToonz - OpenToonz is an animation program that is a free software version of Toonz, the animation software...
Synfig Studio - Just another WordPress site
Spine - Spine is 2D animation software designed specifically for software and game development.
Pencil2D - Pencil2D is an opensource animation/drawing software for Mac OS X, Windows, and Linux, based on old...
CrazyTalk Animator - CrazyTalk Animator, the next level of 2D animation. Create actors using any photo or illustration.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.