Patents and the MIT License
Some of my software projects use MIT so I have studied this issue. Although in many respects the world has moved on from copyright wars to much higher-stakes legal shennanigans, the detail of licensing still matters.
In my case:
- My LumoSQL project is based on probably the most-used software, SQLite, whose license states it is in the “Public Domain”. The meaning of this isn’t entirely clear in some cases, and a 21st century software project starting decades after SQLite shouldn’t copy this.
- I chose MIT as a commonly accepted alternative, but which license is that exactly, and what does the text imply about patents? This is known, but I had to dig.
- The MIT license is massively used, but who will defend it if needed? We know the answer for the GPL, and also Apache-type licenses. I am now satisfied that quite a lot of enormous organisations really do care about MIT.
- There are lots of reasons why MIT isn’t ideal, but in my view those are trumped by it being widely accepted as fit for purpose, and relied upon by organisations who care that it remains effective and unambiguous.
My notes are mostly kept in my many contributions to the Wikipedia page on the MIT License since that is where the decades-old knowledge of the MIT license origins is already maintained. The legal minds in many of the largest companies in the world seem to accept that at least in the US the MIT license implies a patent grant. As probably the most-used open source license, the MIT license has many wealthy corporate defenders if anyone wanted to test that idea.