Chapter 15. License or Contract?
One significant unresolved legal issue in open source licensing is whether licenses like GNU General Public License (GPL) and GNU Lesser General Public License (LGPL) should be characterized as contracts. As a baseline, most licensing agreements are just that: agreements. Documents like the GPL, though, specifically state they are not contracts.
In theory, the GPL and similar documents are licenses granted simultaneously to all who wish to take the code under that license, and their restrictions operate as conditions to the license rather than as contractual obligations. Many people, and particularly lawyers who are accustomed to dealing with software license agreements, find this quite confusing.
Under the law, a contract is a promise or series of promises made by two or more parties. Promises are sometimes called covenants, but there is no magic about this; a covenant is merely a somewhat old-fashioned word for a promise. Under law, to have a binding contract—one that will be enforced by the law—there must be an offer, an acceptance, and consideration. Consideration is the giving of something of value, or quid pro quo. The law does not generally inquire into whether the bargain is fair or even, but each party has to promise something, even if that something is only to forbear doing something the party would otherwise have the right to do.
Open source licenses clearly involve an offer: The licensor makes the software and ...