GitHub Stats and Facts
GitHub is the best place to share code with friends, co-workers, classmates, and complete strangers. Over four million people use GitHub to build amazing things together. (source)
Please note that some of these numbers are easier to find than others. A few of these stats come from the company’s own reports, but some are based on news reports and not official company tallies. Basically, this is the best I can find and I don’t guarantee anything to be 100% accurate.