"The Beerware License" Considered Harmful

Initially published on 2010-07-10.

The proposed boilerplate of the license is as follows:

/*
 * ----------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42):
 * <phk@FreeBSD.ORG> wrote this file. As long as you retain this notice you
 * can do whatever you want with this stuff. If we meet some day, and you think
 * this stuff is worth it, you can buy me a beer in return Poul-Henning Kamp
 * ----------------------------------------------------------------------------
 */

<phk@FreeBSD.ORG> wrote this file.

The wording of this is astonishingly careless. And the sentence immediately after it, requires users of the code to “retain this notice” forever.

Why careless? For example:

• What if I want to use a portion of “this file” in another, my own file? Am I now required to “retain” the Beerware notice by copying it into my file? But it would be plainly incorrect there, since it says “[that person] wrote this file” (as in: all of it).
• What if I take “this file” and add many new functions to it, or modify the existing code substantially. The Beerware notice will continue to say that the original author “wrote this file”, and that would not simply be incorrect, but would also diminish the value and extent of my and other third party contributions to “this file” by attributing the whole file to the original author.

If you want to give users an all-permissive license on the code you write, I propose what I call The MIT-Zero License. Also, you should take a look at the Creative Commons' CC0 variant. And if you are fine with requiring “but please keep this copyright notice”, just use the MIT License or the three-clause BSD License. This will ensure that your code can be used as widely as possible, with no license compatibility issues of any kind.