Yes, much of GitHub's core infrastructure is written in C.

That's awesome. You don't find many people that enjoy writing in C. I assumed it was Ruby.

Ruby MRI and YARV are both written in C, so to be a true Ruby hacker you need some C chops. :-)

Interesting. I've heard that thrown around before, but I've never heard someone say the same thing about Python, even though the main Python implementation is C.

Really? Lots of the most famous Python modules are partially implemented in C(++) for performance reasons too, it's not exclusive to Ruby.

For example, Numpy is 56% C. https://github.com/numpy/numpy

From my own experience with Ruby and MRI, there's quite a strong culture of "transparency of code". It's not unusual if you're really down into some "interesting" problem to delve first into your gems/frameworks, and eventually even into MRI itself. Being a PL polyglot pays off in spades in these cases, since you get a solid understanding of the underpinnings of everything.

Note that there's very rarely any need to go there, but the fact that it's both possible and culturally encouraged makes a huge difference for those of us who've needed it.

From the Python docs:

https://docs.python.org/3/

Extending and Embedding tutorial for C/C++ programmers

Python/C API reference for C/C++ programmers

... right between "Distributing Python Modules" and "FAQs"

I have a talk at a Ruby conference last week and even put a small amount of assembly on the screen... While many Rubyists aren't expert C programmers, they know enough to look at Ruby's source every once in a while to figure out what's going on.

Yes. We have open positions for C engineers.

Look at the bottom of the blog post for commits involved in merging these changes upstream for Git 2.0. They are all from vmg.

"so we ported his C++ implementation to C to be backwards compatible"