There are a number of important caveats to the data presented here:
15.653%
Google Project Hosting: 
Google Code Search Results: 7,080,000
0.415%
Google Project Hosting: 
Google Code Search Results: 186,000
0.209%
Google Project Hosting: 
Google Code Search Results: 94,500
15.653%
Google Project Hosting: 
Google Code Search Results: 7,080,000
0.415%
Google Project Hosting: 
Google Code Search Results: 186,000
0.209%
Google Project Hosting: 
Google Code Search Results: 94,500
This website retreives result counts from Google Code Search for each of the listed licenses. On each page view, the site picks the license with the oldest data and checks to see if it is over a day old. If so, a new search is performed, the data is stored, and the percentage recalculated.
This site is copyright © 2009 to Michael Bernstein. The site's code is available under the GNU AGPL 3.0.
This site is coded in Python, runs on Google App Engine, and uses Google's GData API. The Dojo toolkit is used to display the two sorting options.
The Sweetie icons are copyrighted © 2003-2007 to Joseph North who has released them under the Creative Commons Attribution Sharealike 3.0 license.
The Typogridphy CSS framework is copyright © 2008 to Harry Roberts.