From the "GPLv2 and later' files:

It was two years ago on June 29, 2007 that the GPL version 3 was finalized. The GPL is the cornerstone free/open source license in use, and at the time of the version 3 update there were many questions raised about how widely the new license would be adopted.

According to new data from Black Duck, GPLv3 use has quadrupled since 2008, though overall use of GPLv3 is still dwarfed by GPLv2 usage.

Black Duck reports that there are now 9,500, GPLv3 licensed applications. That's up from 2,345 GPLv3 applications in 2008. GPLv3 now represents 5.10 percent of open source licenses currently in use.

In contrast, GPLv2 represents 50.06 percent of all open source licensed software.

Clearly GPLv3 has a very long way to go to catch up to GPLv2 - if it ever will.

Back when debates around the GPLv3 were very active, Linus Torvalds publicly stated on numerous occasions that the Linux kernel would not move from GPLv2 - and so far it hasn't. As long as that position remains the same - and I see no reason why that will ever change - GPLv2 will remain a critically important license.

That doesn't mean that GPLv3 isn't important.

With the new Black Duck data, it is clear that GPLv3 is important.

While GPLv2 still dominates, GPLv3 is just marginally behind the BSD license which sits at 6.32 percent. Black Duck is estimating that GPLv3 will actually pass the BSD license in about 6 months time.