Inkscape

Inkscape is a vector graphics editor application. Its stated goal is to become a powerful graphic tool while being fully compliant with the XML, SVG and CSS standards.

Inkscape is primarily developed for Linux, but it is cross-platform and runs on Mac OS X (under X11) and other Unix-like operating systems, as well as Microsoft Windows. Inkscape's implementation of SVG and CSS standards is incomplete ? most notably, it does not yet support animation, or SVG fonts. Inkscape has multi-lingual support particularly for complex scripts, something currently lacking in most commercial vector graphics applications.

Come to learn more about: http://inkscape.org/download/