Firefox released data from Test Pilot — their framework for collecting Firefox usage data from users that opt-in and install it — and asked people to visualize it. The data is represents one week of Firefox usage for ~270,000 people, and ~4,000 of them also filled out a survey with basic demographic information. I was interested in what usage looked like over time and by age group, so I pulled out Python, sqlite, and R for exploration and used Illustrator to clean it up.

Read more: http://blog.tom-haynes.com/2010/12/firefox-usage-visualization/