Tigris lists the open source license that each project is using. The following chart shows the licenses used by projects on Tigris, and how many projects use each. Note that UNLIKE some other forges, variations of the GPL (and other licenses with multiple versions) are not differentiated by version, rather they are all lumped together.
Here is the SQL needed to generate the data set from the FLOSSmole database:
SELECT license, count( * )
WHERE datasource_id = [current datasource_id]
GROUP BY 1
ORDER BY 2 DESC