Just a quick note - people have been asking me lately how Buildhive (free builds for open source hosted on GitHub) hooks in with GitHub - specifically - how does it know to build a commit or a pull request.
Well, the secret sauce is OAuth - specifically when you signed up to GitHub you would have been asked for various permissions (some of them may have sounded scary to some of you - hopefully will get better as OAuth permission scopes become more fine grained one day).
Well the reason for those being asked is so that it can set up webhooks (ie a GitHub is told to POST to a certain URL when a commit event happens).
In your repo, in the Admin section, you can see Service Hooks - click on it - and then right at the top, you will see WebHook URLs:
(eg see above - this is for my https://github.com/michaelneale/pingtown project).
This is kind of nice - so when you sign up for buildhive - all you have to do is enable a project - and go ! We are always improving the project type detection and support - so in an ideal world it can Just Work (of course in reality, you will want to tweak your build, or it won't detect correctly) - but we can dream !