Getting to Know the MIT License

When licensing your code-based products on Blender Market, you have two options to choose from: GPL and MIT. We discuss the GNU GPL elsewhere (here and here, to be exact), so this article is dedicated to the MIT license.

I've heard a couple of different licenses called the "MIT License". Which one are we talking about?

The GNU GPL website identifies a couple of licenses that have been called the "MIT License": the Expat and the X11. The MIT License that we use here at Blender Market is the Expat/MIT License.

What important differences are there between the GPL and MIT licenses?

The MIT License puts fewer conditions on software usage than the GPL. As noted above, it is what's known as a "permissive" license, which "allow[s] you to do whatever you want with the software as long as you abide by notice requirements" (Meeker 2020, 41).

The MIT license does not require that you provide source code. But, if portions of your MIT-licensed program build upon existing code that is licensed as GPL, for example, the Blender API, you will need to provide the source code.

The MIT license also provides no patent protection (the GPL does).

Finally, the person who purchases your MIT licensed product buys it "as-is" and cannot hold you liable for issues with the software ( tl;drLegal).

What does it mean to give notice (and how do I do it)?

Pay particular attention to this line in the middle of the license text:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

One of the requirements of the MIT license is to provide "notice"—in this case, copyright notice and permission notice. What this means is that you need to include a copy of the license with your product files. So, copy and paste the full license text into a text file, add the relevant copyright info, and upload that license file to Blender Market along with your product files.

GPL vs. MIT comparison

This list is not exhaustive, nor is it legal advice—the full text of the GPLv3 can be found here and the text of the MIT License can be found here.

In the table below, y = yes, n = no, w/p = with permission.

License Type:	GNU GPL 3.0	MIT
Allow redistribution	y	y
Allows modification	y	y
Allows personal use	y	y
Allows commercial use	y	y
Requires License & Copyright Notice be included with software	y	y
Requires source code be made available	y	n
Requires same or similar license when redistributed	y	n
Requires that changes to the licensed material be documented	y	n

References

Meeker, Heather. Open Source for Business. Seattle, SC: Kindle Direct Publishing Platform, 2020.