The Language of Freedom

Open source licenses promise to everyone what many in the community refer to as software freedom. The terminology of freedom is emotionally satisfying, but it has proven to be very confusing.
Freedom is an important subject in law school. Constitutional law courses address such topics as the free speech clause of the First Amendment to the U.S. Constitution. But freedom seldom comes up as a topic in classes devoted to business issues such as contract or tort law, or software licensing. Law school courses on intellectual property deal with copyright and patent, but they don’t teach about freedom, referring instead to the rights of the owners of those legal monopolies.
As a result, there is no easy conceptual basis for integrating the language of freedom into the legal language of software licenses. For example, where the word free is currently used in software licensing contexts, it usually means zero, as in free of charge or free of defects.

Neither of these meanings is intended by open source licenses.

Not that software freedom isn’t definable. The Free Software Foundation lists four essential kinds of software freedom:

1. The freedom to run the software for any purpose
2. The freedom to study how the software works and to adapt it to your needs
3. The freedom to redistribute copies of the software
4. The freedom to improve the software and distribute your improvements to the public

That list, it turns out, can be satisfied by many different software licenses. Both the GPL and the BSD licenses, the earliest open source examples from the late 1980s, ensure those four kinds of software freedom, although they do it in vastly different ways.
Proprietary software vendors love the software freedom provided by the BSD license, but some of them hate and fear the software freedom guaranteed by the GPL. So once again, the concept of freedom by itself is only marginally helpful to understanding open source licensing.