Blender is a 3D modelling and rendering package. It is the in-house
software of a high quality animation studio, Blender has proven to
be an extremely fast and versatile design instrument. The software
has a personal touch, offering a unique approach to the world of
Three Dimensions. Use Blender to create TV commercials, to make
technical visualizations, business graphics, to do some morphing,
or design user interfaces. You can easy build and manage complex
environments. The renderer is versatile and extremely fast. All
basic animation principles (curves & keys) are well implemented.It
includes tools for modeling, sculpting, texturing (painting,
node-based shader materials, or UV mapped), UV mapping, rigging and
constraints, weight painting, particle systems, simulation (fluids,
physics, and soft body dynamics and an external crowd simulator),
rendering, node-based compositing, and non linear video editing,
as well as an integrated game engine for real-time interactive 3D
and game creation and playback with cross-platform compatibility.
http://www.blender.org