"..RMS’s other mission here is to promote the Free Software Movement. The creator of the GPL...is at pains to correct misunderstandings of what the term free software means and to draw a distinction between it and the open source movement.

“Open Source” advocate: «...I associate much more with the "Open Source" (also as Richard defines it) camp, and am open to the existence and use of proprietary software...» --

"Open source is a development methodology; free software is a social movement. For the free software movement, free software is an ethical imperative, because only free software respects the users' freedom. By contrast, the philosophy of open source considers issues in terms of how to make software “better”—in a practical sense only. It says that non-free software is a suboptimal solution.

"As the founder of the free software movement and author of the GNU General Public License, I am writing to correct a misleading characterisation of free software presented in William Venema's article about open source. National Law Journal, Oct. 20. I do not wish to defend open source, which I have never supported.

"...The first thing we see is that the organization ducks the issue of users' freedom; it uses the term "open source" and does not speak of "free software". These two terms stand for different philosophies which are based on different values: free software's values are freedom and social solidarity, whereas open source cites only practical convenience values such as powerful, reliable software..."

"...In 1998, some of the people in the free software community began using the term "open source software" instead of "free software" to describe what they do. The term "open source" quickly became associated with a different approach, a different philosophy, different values, and even a different criterion for which licenses are acceptable. The Free Software movement and the Open Source movement are today separate movements with different views and goals, although we can and do work together on some practical projects..."

RMS: «...Their stated definition for the term “open source” is somewhat broader than free software, and thus includes my work. But describing the GNU GPL as an “open source license,” as Microsoft did, is more than half misleading. The GNU GPL embodies the firm philosophy of the free software movement; it doesn't come from the open source movement.

"...For the Open Source movement, the issue of whether software should be open source is a practical question, not an ethical one. As one person put it, “Open source is a development methodology; free software is a social movement.” For the Open Source movement, non-free software is a suboptimal solution.

The free software movement is one the most successful social movements to emerge in the past 25 years, driven by a worldwide community of ethical programmers dedicated to the cause of freedom and sharing. But the ultimate success of the free software movement depends upon teaching our friends, neighbors and work colleagues about the danger of not having software freedom, about the danger of a society losing control over its computing.