Most active GitHub users (git.io/top)
The count of contributions (summary of Pull Requests, opened issues and commits) to public repos at GitHub.com from Sun, 02 Jun 2013 04:57:42 GMT till Mon, 02 Jun 2014 04:57:42 GMT.
Only first 1000 GitHub users according to the count of followers are taken. This is because of limitations of GitHub search. Sorting algo in pseudocode:
githubUsers
.filter((user) -> user.followers > 273)