The free-software movement refers to those people who advocate the principles of free software (in the freedom sense). Richard Stallman is one of the founders and major proponents of the movement, whose adherents sometimes say they belong to the "Free World".
Members of the free software movement believe the software freedoms listed on free software should apply to all software: they hold that it is immoral to prevent people from excercising these freedoms. Richard Stallman argues that non-free software is immoral because it prevents its users from learning and from helping their fellow man. There is no consensus, however, how these aims should be met. Some believe that software should be freed through legislation; others through boycotts of proprietary software. Still others believe that time will tell, as free software will eventually be technically superior to proprietary software, and will win on the free market.
On the other hand, many who prefer the term "free software" and consider themselves part of the movement do not believe proprietary software to be strictly immoral. They argue, however, that freedom is valuable (both socially and pragmatically) as a property of software in its own right, separate from technical quality in a narrow sense. Moreover, they may use the term "free software" to distance themselves from claims that "open-source" software is always technically superior than proprietary software (which is often demonstrably false, at least in the short term). In this sense, they object that "open source" advocates, by concentrating solely on technical merits, encourage users to sacrifice their freedom (and the long-term benefits thereof) for short-term conveniences that proprietary software may provide.
Supporters of Open Source argue for the pragmatic virtues of free software (aka "open source software") rather than questions of morality. Their basic disagreement with the Free Software Foundation is its blanket condemnation of proprietary software. There are many programmers who enjoy supporting and using free software but make their livings developing proprietary software, and do not consider their actions immoral. The "official" free-software and open-source definitions are slightly different, with the free-software definition generally considered to be more strict, but in practice virtually all open-source licenses in use are also free-software licenses.
Many members of the Free Software Movement believe that also other materials currently subject to copyright and patent law should be freed. Some believe that some classes of works should not be freely modifiable, e.g. opinion pieces in order to prevent misrepresentation of the author's beliefs, fictional works, or licenses themselves.