Internet Governance Glossary
Software that respects users' freedom and community, which means that the users have the freedom to run, copy, distribute, study, change and improve the software.
Thus, “free software” is a matter of liberty, not price. To understand the concept, you should think of “free” as in “free speech”, not as in "free beer". We sometimes call it “libre software” to show we do not mean it is gratis.
Free software does not necessarily mean free-of-charge software.