Mailing the story:

Pulse is a build server that can monitor your source repository and trigger a build and test cycle every time somebody does a commit. With Pulse you will always know if the most recent sources in your revision control system compile and if they pass your unit and system tests. Better yet, Pulse allows you to build and test your current working copy of checked-out source, during a so-called Personal Build, so you can see if your code breaks things before you commit your changes to the central repository.