Why I love the MIT license
As software developers, we face code licensing every day. We intentionally or unintentionally use open source software libraries that put several liberties and constraints onto ourselves. And if we develop code with potential value to others, we may consider open sourcing it under a certain license.
One of the most successful open source licenses is the MIT license. It was chosen for the X11 window system, Ruby on Rails, React and many of today’s web technologies. Here’s the full license text.
MIT License
Copyright (c) [year] [fullname]
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.Can you believe this? That’s just three paragraphs! This is what I love about this license. It’s short and it’s written in plain clear english. You don’t need to ask a lawyer about what it means. Read it, and you know exactly what you’re at. I once heard someone describe the license like this.
Do whatever the fuck you want, as long as you don’t sue me.
Maybe that’s not how a lawyer would phrase it, but it’s pretty much to the point. Compare this to other popular licenses such as the GPLv3. You have to read pages of legal speak that put all sorts of constraints onto the user of the licensed code.
This shortness and clarity in writing of the MIT license goes hand in hand with its philosophy of granting maximum freedom onto the user of the licensed code. Fewer constraints means less complexity, which enables shorter, clearer writing. That’s also the reason why the MIT license is part of a family of licenses that are called permissive. You are allowed to do whatever you want with the licensed content, as long as you don’t hurt its publisher.
I really like this “live and let live” philosophy of the MIT license. Copyleft licenses such as the Gnu GPL are much stricter. While most copyleft licenses allow the usage of the licensed content for both private and commercial use, they usually (1) require any changes made to the content to be open sourced under the same license and (2) prevent relicensing the content under a more permissive license. Some licenses such as the GPL don’t even allow using the code as a library you link to from a proprietary code base, even when the licensed code is not changed (the LGPL allows this though).
The Gnu project deserves much praise for the work it has done, but I never liked its ideology-driven philosophy that somewhat demonizes commercial software and tells people which kind of sharing is morally acceptable. It feels like socialist policy, “here’s free stuff, but you have to do this and that for it and you’re not allowed to have a different opinion”. The MIT license on the other hand must have been written by a libertarian: “Do whatever you want, as long as your behavior doesn’t punish me.”
In recent years, the success of open source software has been tremendous and any doubts on whether open sourcing code and commercial activity can go hand in hand have been wiped out. In fact, open sourcing reusable code and making it available for the community free of charge is seen as beneficial even by companies like Microsoft. Very often, famous open source software that originates from commercial use is licensed under a permissive license like the MIT license.
When writing code, we all agree that simplicity is a worthwile goal. We should strive for simplicity in the way we license and share our code, too.
