Protovis is free and open-source, provided under
the BSD
License. It uses JavaScript
and SVG for web-native
visualizations; no plugin required (though you will need a modern web
browser)! Although programming experience is helpful, Protovis is
mostly declarative and designed to be learned by
example.

This project was led by Mike Bostock and Jeff Heer of the Stanford Visualization Group, with
significant help from Vadim Ogie…