Test Pilot is a research program launched in 2009 by Mozilla Labs to learn about how people use Firefox. It's strictly anonymous, opt-in, and unlike most data-collection programs, it gives users the chance to see exactly what data has been collected before they choose whether to upload it. Aggregated and sanitized data samples are released to the public under a Creative Commons license to encourage community participation in analysis. Over half a million users have submitted log data about how they use tabs, menus, toolbars, bookmarks, searches, and other browser features. Jono will talk about how Test Pilot works, share interesting and surprising things we've learned so far, and answer questions about our methodology.