This session was based on statistics that has been published in a couple of blogs:
There was then interesting discussion around this, why is that, etc? The blog posts above already cover most of it.
An interesting comment I hadn't thought of before: Maybe one reason PHP didn't grow as big as Perl and Python was the lack of a solid legal incorporation. Apparently there have been tensions between Zend and the community (back in the day...)
At the end of the session we asked ourselves what the future looks like. For which we obviously have no statistics. We discussed how most projects on Github don't even have an open source license, let alone a foundation.
The OpenStack patch review / CI process was also mentioned as an example of a project that has scaled big and fast. By popular request Mark Atwood did a session on this topic on Sunday.