San Francisco, California
from the github web site
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.
With the <a href="https://github.com/features/">collaborative features of GitHub.com</a>, our <a href="http://mac.github.com/">desktop</a> and <a href="http://mobile.github.com/">mobile apps</a>, and <a href="https://enterprise.github.com/">GitHub Enterprise</a>, it has never been easier for individuals and teams to write better code, faster. Originally founded by <a href="https://github.com/mojombo">Tom Preston-Werner</a>, <a href="https://github.com/defunkt">Chris Wanstrath</a>, and <a href="https://github.com/pjhyett">PJ Hyett</a> to simplify sharing code, GitHub has grown into the largest code host in the world.
More information available on the github's web site.
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