What Is a License?

I've used the word license quite loosely in the preceding chapters, waiting for an opportune time to explain that word from a legal perspective. In one sense, a license is a permission to do something. The government issues licenses, such as a license to drive a vehicle on the public right of way or a license to run a business, pursuant to laws regulating such activities. The government tells you that you may not drive a car or engage in business without an appropriate license. You are required to obey the traffic laws and the laws regulating businesses, although the license you bought has nothing to do with those obligations. If you exceed the speed limit or if you engage in a fraudulent business practice, you can be penalized even if you didn't bother to get an appropriate license.

An owner of a private property right can grant licenses to allow others to exercise property rights that otherwise would be exclusive to the property owner. For example, the owner of beachfront property can license a telescope club to pass onto the beach to witness a solar eclipse. (There are subtle differences between this kind of license and an easement that grants access to real property, about which nothing more will be said in this book.) Such licenses can be limited as to time. They may grant rights only to specific people or to the public as a whole.

In this book, the term license is used to describe the legal way a copyright and patent owner grants permission to others to use his intellectual property.

An open source license is the way a copyright and patent owner grants permission to others to use his intellectual property in such a way that software freedom is protected for all.

A proprietary license is the way a copyright or patent owner grants permission to others to use his intellectual property in a restricted way, through secrecy or other limitations, so that software freedom is not protected.

The word proprietary is often confused with the word commercial . But a commercial license “ which is merely a term used to describe a license used in commerce “ can be either open source or proprietary.

Licenses can be express or implied . An express license is typically a written document that is reviewed and agreed to by the owner of the licensed property (the licensor ) and by the receiver of the license grant (the licensee ). All of the licenses described in this book contain at least some express written terms and conditions.

A license may also be implied by the kind of license being granted, by the conduct of the licensor, or by the licensor's apparent refusal to exercise its exclusive rights to the licensed property. In one very important example, some open source licenses say nothing about a grant of patent license, leaving the patent license to implication .

Be careful about implied licenses. An implied license is necessarily vague and incomplete. The terms and conditions of an implied license may not be clear to either the licensor or the licensee. Reliance on an implied license is particularly risky when important property interests are at stake.