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The MIT License does not use the word "patent", but there are good arguments that MIT grants at least an implied patent license, perhaps even a (limited) expres

The MIT License does not use the word "patent", but there are good arguments that MIT grants at least an implied patent license, perhaps even a (limited) express patent license. "Implied patent license" is the search string if you want to read more. Apache version 2.0, on the other hand, has an express patent license. There are very good reasons to prefer an express patent license.

mcherm 11y ago
> there are good arguments that MIT grants at least an implied patent license, perhaps even a (limited) express patent license. I have not heard such arguments before. Can you provide a link to someplace where these legal arguments are explained?
- kemitchell 11y ago
  I don't know a single online source worthy of recommendation, so I'm afraid you'll have to do your own searching. But in a nutshell, at least under US law: 1. The permission language "deal in the Software without restriction" is very broad. 2. Of the more specific, enumerated permissions "use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of" the terms "copy", "modify", "publish", "distribute", and "copies" speak to the exclusive rights of copyright owners per United States Code title 17, section 106. The terms "use" and "sell" speak to things you can sue for under a patent per United States Code title 35, section 271. The term "sublicense" is generic to licenses of all kinds, including copyright licenses and patent licenses. 3. There is also a legal idea called "estoppel" that prevents, broadly speaking, leading people to believe they can violate your rights freely and then suing them, or taking back or shrinking permission that you've already granted. State Contracting and Engineering Corporation v. Florida, decided by the United States Court of Appeals for the Federal Circuit, is an interesting case in the patent context. You might find a summary online, if you haven't time to trawl through the court's written opinion. To quote Larry Rosen, from his book Open Source Licensing: > 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 risk when important property interests are at stake. If you're worried about an implied license for a specific reason, please talk to your company's legal or engage an attorney. It's going to require a judgment call, and you want someone on your side who will consider a lot more than what I've mentioned here in coming up with good advice.
  - mcherm 11y ago
    Thank you! Incomplete though that may have been, it still was very educational.

mcherm 11y ago

> there are good arguments that MIT grants at least an implied patent license, perhaps even a (limited) express patent license. I have not heard such arguments before. Can you provide a link to someplace where these legal arguments are explained?

kemitchell 11y ago
I don't know a single online source worthy of recommendation, so I'm afraid you'll have to do your own searching. But in a nutshell, at least under US law: 1. The permission language "deal in the Software without restriction" is very broad. 2. Of the more specific, enumerated permissions "use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of" the terms "copy", "modify", "publish", "distribute", and "copies" speak to the exclusive rights of copyright owners per United States Code title 17, section 106. The terms "use" and "sell" speak to things you can sue for under a patent per United States Code title 35, section 271. The term "sublicense" is generic to licenses of all kinds, including copyright licenses and patent licenses. 3. There is also a legal idea called "estoppel" that prevents, broadly speaking, leading people to believe they can violate your rights freely and then suing them, or taking back or shrinking permission that you've already granted. State Contracting and Engineering Corporation v. Florida, decided by the United States Court of Appeals for the Federal Circuit, is an interesting case in the patent context. You might find a summary online, if you haven't time to trawl through the court's written opinion. To quote Larry Rosen, from his book Open Source Licensing: > 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 risk when important property interests are at stake. If you're worried about an implied license for a specific reason, please talk to your company's legal or engage an attorney. It's going to require a judgment call, and you want someone on your side who will consider a lot more than what I've mentioned here in coming up with good advice.
- mcherm 11y ago
  Thank you! Incomplete though that may have been, it still was very educational.