
The level of programming required to use and modify the tools is slightly above that of HTML but easier than JavaScript, a common Web scripting language. One of the main benefits of Protovis is that it is structured in such a way that a person who thinks first in terms of visualizations and then in terms of data should be able to find it easy enough to use. Instead of having to focus on how to structure code for the program, Protovis lets a user create simple building blocks, such as the colors and shapes needed for the visualization, then piece the blocks together to define the complete picture. One example of the type of visualizations that are made easier with Protovis is called Job Voyager.
More information:
http://vis.stanford.edu/protovis/
http://technologyreview.com/computing/22927/