> Imagine, for example, the vast public good that would arise from Google or Microsoft opening up their entire code bases for free.

Why stop with code? If code is always better in the open, then why not require all business communication in the open.

> in any business there exists a tension between private profit and public good

I don't think there is always a tension. If not by profit, how do you motivate people to develop new technology and fund the support system necessary for development?