title: What is the difference between author and committer in Git?
body: <p>I just came across the following commit on GitHub:
  <a href="https://github.com/felixge/node-formidable/commit/0a0b150668daa3c6f01626d2565b898e5da12392">https://github.com/felixge/node-formidable/commit/0a0b150668daa3c6f01626d2565b898e5da12392</a></p>
  
  <p>How does one go about having multiple authors on the same commit like that?</p>