(Author here.) This started as an idea for a clever visualization but turned into a mammoth amount of work. OpenStack, GitLab, the kernel, Chromium and Apache do not use GitHub (or are only mirrored there).

I'm happy to hear ideas for improvements.

Have a look at http://grimoirelab.github.io, which supports many of the data sources for those projects (but still, you need work to retrieve everything, and analyze, and stuff...)

Yes, this was a big job -- one of the reasons I stopped working on something similar 1.5 years ago was that I wasn't capturing the non-GitHub activity. Of course that back then I also wasn't controlling for bots.

I'm hoping the incremental work to maintain this won't be too much trouble and we can release a new version every quarter or so.

Thanks for going out of your way to add support for GitLab!

I've also checked FreeBSD, and it would be in Top 30 too.

Hey, you worked on the project as a freelancer, right? Would you be interested in chatting with me about how to do this again in the future?