Blender
Blender is a free and open source 3D creation suite that supports the entirety of the 3D pipeline—modeling, rigging, animation, simulation, rendering, compositing and motion tracking, video editing and game creation. Blender features a powerful unbiased rendering engine called Cycles that offers stunning ultra-realistic rendering. Experience the joy of sculpting organic subjects using the built-in sculpting feature set of Blender. Whether it’s simple keyframing or complex walk-cycles, Blender allows artists to turn their still characters into impressive animations. Blender comes with a fully fledged compositor built right in. That means no more exporting to third party programs, you can do it all without leaving the program.