You can download entire Adobe Creative Suite 2 for free directly from Adobe website
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Pencil is a great, simple and free 2D animation/drawing software for Mac OS X, Windows, and Linux. You can download it from
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and, you probably know about them already, but still...

Blender, 3D creation for everyone, free to use for any purpose.
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GIMP, the GNU Image Manipulation Program. It is a freely distributed piece of software for such tasks as photo retouching, image composition and image authoring. It works on many operating systems, in many languages...
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Inkscape, an Open Source vector graphics editor, with capabilities similar to Illustrator, CorelDraw, or Xara X, using the W3C standard Scalable Vector Graphics (SVG) file format.
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