Blender

Blender is an integrated application that enables the creation of a broad range of 2D and 3D content. Blender provides a broad spectrum of modeling, texturing, lighting, animation and video post-processing functionality in one package. Through it's open architecture, Blender provides cross-platform interoperability, extensibility, an incredibly small footprint, and a tightly integrated workflow. Blender is one of the most popular Open Source 3D graphics application in the world.

Features:

• Fully integrated creation suite, offering a broad range of essential tools for the creation of 3D content, including modeling, uv-mapping, texturing, rigging, skinning, animation, particle and other simulation, scripting, rendering, compositing, post-production, and game creation;
• Cross platform, with OpenGL uniform GUI on all platforms, ready to use for all versions of Windows (98, NT, 2000, XP), Linux, OS X, FreeBSD, Irix, Sun and numerous other operating systems;
• High quality 3D architecture enabling fast and efficient creation work-flow;
• More than 200,000 downloads of each release (users) worldwide;
• User community support by forums for questions, answers, and critique at http://BlenderArtists.org and news services at http://BlenderNation.com;
• Small executable size, easy distribution. 

Homepage:

http://www.blender.org/

Download:

http://www.blender.org/download/get-blender/