This one is a Javascript library to produce images for web documents. Here's some sample output:

Source: http://d3js.org/. Note that Python has a nice, cool graphic library as well.

Also, I could not resist to include the following flowingdata image:

Source: http://flowingdata.com/2013/03/22/internet-census/

And one more (word cloud) from http://www.dashboardzone.com/face-off-between-dashboard-and-busines...

Here is the summary of word counts for each vendor

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