In as much as the metadata is accurate, the information can be interpreted in any meaningful way, and considering selection bias for things that people actually

In as much as the metadata is accurate, the information can be interpreted in any meaningful way, and considering selection bias for things that people actually make available via these services (however, if something isn't listed with some index that makes it discoverable, it doesn't matter what the license is): Freshmeat: 21185 projects tagged "GPL", 49 projects tagged "CDDL", 2500 projects tagged "BSD", 1807 projects tagged "BSD Revised", 1311 projects tagged "MIT/X", 1079 projects tagged "Apache 2.0", 314 projects tagged "MPL" Sourceforge: of 1236 "OSI Approved" listed via the search refinement interface, 983 GPLv2, 22 BSD, 10 Apache 2.0, 8 MIT. Unfortunately, neither Github or Oholo provide aggregated license information or it's not easy to find [0]. I did find this two year old post [1] about licenses of the most watched repositories on github, but popularity of the project isn't necessarily an indicator of popularity of the use of the license -- except as much as the type of license indicates which projects people will want to use because the the license lets them contribute. I do vaguely remember some random blog posts that attempted to do license counts in a repeatable and objective way, but my google-fu is failing me right now. These are hardly conclusive numbers, and it becomes difficult to consider it in aggregate. Is all of OpenBSD considered one "project", as it's effectively distributed as one piece, or are the individual components themselves projects? Is everything in GNU core-utils one project? Maybe each binary counts as the use of the license. However, just going by these services' self-promoted "project" delineation being ~10x in favor of GPL (GPLv3, LGPL may or may not be included in the above numbers), the non-GPL licenses seem to be significantly low enough that "The GPL is the world's most popular license" may be a reasonably safe, even if not entirely accurate, position to take. I suspect that if you pick 10 projects at random, more than half of them will be GPL. [0] A four year old post on this not being straight forward on github at that time. https://groups.google.com/forum/#!topic/github/9WH6LtsPYtM https://groups.google.com/forum/#!topic/github/9WH6LtsPYtM [1] http://ostatic.com/blog/the-top-licenses-on-github http://ostatic.com/blog/the-top-licenses-on-github