Goodbye Snow Leopard
Recently, with the vast majority of our users running at least Lion, we made the decision to no longer support Mac OS X 10.6. We also wanted to make use of the improvements available to developers in OS X 10.7 (Lion) and 10.8 (Mountain Lion).
Therefore, going forward, releases of GitHub for Mac will require an install of at least 10.7 to run. If you are running Snow Leopard, you simply won’t see any new updates and can continue to run your existing version.