OpenX is an opensource adserver with similar functionality to other ad services. The difference is that you run the service yourself and it is free if you host it yourself.

I am often faced with Drupal clients who are interested in selling ad space on their sites but don't want to use a paid service, need more flexibility than the ad module available for Drupal, and don't want want to use a service like AdBrite or Google Ads.

This little tutorial will show you how to install the ad server on your localhost to play around with it. First off, you need some kind of *amp stack on your computer. I personally work on a Mac, so I use MAMP. This also means that the tutorial is Mac centric.