Beyond being a good business case, Open Source has many direct and indirect benefits to society.  Open Source has obvious pragmatic advantages for community development processes, most notably in its empowerment of users. But the ideological foundations and social/organizational structure of the free software movement are also consistent with community development at a theoretical level.

Here are some ethical reasons to choose Open Source software:

Compared to traditional software, using successful open source infrastructure components offers some key advantages:

source: A Guide to Developing an Enterprise Open Source Strategy, a MySQL Business White Paper, February 2005.

The concept of “freedom" is very important to the open source community. With its huge community of testers and rapid iteration, the open source approach has been able to produce higher quality code, with fewer defects and fewer security vulnerabilities. In fact, a December 2003 study conducted by Reasoning (a leading provider of automated software inspection services) showed that the code quality of MySQL was six times better than that of comparable proprietary code. This is because a huge community of developers tests the software across a range of platforms before it is certified for production. Bugs are found and fixed quickly. Access to source code ensures a thorough understanding of the system. Developers can also make modifications or performance enhancements as necessary.

from www.opensource.org

"The basic idea behind open source is very simple: When programmers can read, redistribute, and modify the source code for a piece of software, the software evolves. People improve it, people adapt it, people fix bugs. And this can happen at a speed that, if one is used to the slow pace of conventional software development, seems astonishing.