The Intranet Journal has a conside article comparing open source and proprietary intranet software. T It is set to be a three part series, and atleast this first part is general enough to be applicable to most OSS vs. non-free choices.
The article covers the pros and cons in terms of:
- Freedom from “The Man”
- Cost of ownership
- Experienced support communities
- Software customization
- Product longevity
So if you need to convince someone to go with OSS instead of proprietary, take a look.