This paper provides quantitative data that, in many cases, using open source software / free software is a reasonable or even superior approach to using their proprietary competition according to various measures. This paper examines market share, reliability, performance, scalability, security, and total cost of ownership. It also has sections on non-quantitative issues, unnecessary fears, usage reports, other sites providing related information, and ends with some conclusions. You can view this paper at http://www.dwheeler.com/oss_fs_why.html (HTML format). PDF format.
–>Palm PDA users can view it in Plucker format (you will also need Plucker to read it); a short briefing based on this paper is also available (in Open Office Impress format). Old archived copies are also available.