Open source software is awesome, and it's free. What more do you need to know? In all actuality, there's a lot to consider when thinking about what software to use in your startup. Do you go with open source or proprietary? Maybe Google can help.
Chris DiBona, Director of Open Source at Google, is interviewed by Don Dodge about how your startup should use open source software. It's a given that you should use open source and perhaps contribute as well, but there are tricks to doing it correctly, so that you can scale, so you don't run into legal trouble and so that you can be acquired.