title: How do I mirror and synchronize GitHub and SourceForge repositories?
body: <p>I have a repository on GitHub and an empty repository at SourceForge. How do I make mirrors and synchronize them? </p>
  
  <p>On StackOverflow there is "<a href="https://stackoverflow.com/questions/13382415/mirroring-a-repository-across-github-sourceforge-and-google-code">Mirroring a repository across Github, Sourceforge and Google Code</a>" which explains how to push to multiple repositories, but how do I synchronize them when commits will be in GitHub or SourceForge?</p>