Strange but true software licenses: No foolin’

Unusual open source licenses

Drinking games

There are a few variations on the Beerware theme.

Beerware
Authored by Poul-Henning Kamp, this is a concise attribution-style license, meaning a developer can appropriate the software but must retain the license with the code. It became well-known for gently suggesting that you buy the copyright holder a beer if you find the software useful.

Drinkware
The Beerware License, but modified to allow the copyright holder to parameterize with another type of drink. It’s very flexible in this regard: coffee, martini, Veuve Clicquot? It’s up to the licensor.

Strong Beerware
The Black Duck Audit team coined the name of this one. Clearly inspired by the Beerware License, it’s actually the MIT License but with the obligation to buy the copyright holder a beer. In recent years, we’ve seen even license-conservative companies like Google get comfortable with the Beerware License, but the obligatory nature of this one is likely beyond the risk tolerance of most IP attorneys.
 

Theater of the absurd

These are clearly satirical, implicitly making fun of IP law, and at least trying to be amusing. Most are somewhat clever. You be the judge. We believe all these have actually been attached to software.

In addition, after the full license list, you will find links to a couple of sites that house parody licenses penned by the site owners purely for amusement (their own?), not actual use.

Death and Repudiation License
This one starts out, “This software may not be used directly by any living being,” and goes on to allow for use only after death. It should be pointed out that the copyright holder offers the BSD license as an alternative, “you lucky stiff.”

Solipsistic Eclipse Public License
Get out your dictionary and philosophy text to appreciate this one. It includes definitions such as, “The term ‘you’ refers to the only being who verifiably exists.” It kind of says you can use the software as long as you will swear it doesn’t exist. The Apache Foundation isn’t amused and includes it on its “Category X” (just what it sounds like) list.

Bantown Public License
The preamble conveys the idea, “The licenses for most software are designed to allow you to use the software in a legitimate enterprise. By contrast, the Bantown Public License is intended to make sure you can only use software for criminal conduct.” Ha ha.

Chicken Dance License
It works like a reciprocal license, with the requirement that source code accompany binary distribution, but it can be alternatively satisfied by posting a video on social media of employees performing the Chicken Dance. The author, Andrew “Tuna” Harris, went as far as to apply for formal recognition by the Open Source Initiative, which didn’t buy it and dismissed the application as frivolous.
 

#$@#&^ software licenses

Licenses that resort to satirical profanity could be considered a subset of the class satirical/absurd class, but most have some point, and profanity aside, some are legally interpretable.

WTF Public License
This crazy license is the one that shows up the most commonly. The gist is that you can do whatever (the eff) you want with the software. Ultrapermissive. It was once on Google’s verboten list, though more recently it started categorizing it as an acceptable attribution-style license.

Good Luck with That S* Public License
Similar in spirit to the WTFPL, except that it’s somewhat the opposite of attribution-style. It explicitly disallows giving attribution to the copyright holder. WTF? (There also a version with cleaned up language on the SPDX list.)

DBAD Public License
The license prohibits being a d* and defines such behavior by providing examples having to do with disrespecting the copyright holder’s intellectual property. It also raises a glass to the Beerware License by describing that d-ish behavior would include making money from the work and not buying a pint for the creator of the work. This is another of the three licenses classed as “nonsensical” in Apache’s Category X list.

Ad hominem

There are a number of licenses that restrict use by certain individuals or categories of persons. The licenses range from satirical to ludicrous.

Anyone Except Richard Stallman License
It allows for any possible use except by Richard Stallman, the originator of open source licensing. One version, the Anyone but Richard Stallman License, also suggests that anyone making “a zillion bucks off this” should buy a homeless person a meal.

No Bob Saget Open Source License
The MIT License with a carve out prohibiting use by late comedian Bob Saget and restricting all licensees from distributing to Bob Saget.

Nonwhite-Heterosexual Male License
While the license does not prohibit use by white hetero males, it does place additional attribution requirements (which are otherwise voluntary) on that class of individuals.

Che Guevara License
The BSD license with an additional prohibition of any use by “owners of Che Guevarra (sic) paraphernalia…if possible….” It gives the impression of being a goof, rather than a political message.
 

Do the right thing

The last class of licenses includes seemingly well-intended ethically based restrictions on licensees and field of use. Bad things can be in the mind of the beholder, and so many of the restrictions are ambiguous. In our experience, the restrictions in these licenses and the ambiguity give most IP attorneys pause.

JSON License
This is the best-known and most-used do-gooder license. It’s the MIT License plus nine words added by JSON-creator Douglas Crawford: the Software shall be used for Good, not Evil. The ambiguity turned out to be problematic to the point that, after some attempts at negotiation, the license ended up on the Apache nonsensical list (a little harsh, perhaps). After an inquiry from IBM, Crawford showed considerable flexibility in creating the IBM exception that reads “I give permission to IBM, its customers, partners, and minions, to use JSLint for evil.” Heck of a guy!

Code Project Open License
We run into this one frequently. It’s a custom, attribution-style license with a clause that tends to get attention: “You agree not to use the Work for illegal, immoral, or improper purposes, or on pages containing illegal, immoral, or improper material.”

For Good Eyes License
Essentially a custom weak copyleft license with the provision that “The licensee is not allowed to behave in unethical ways or ever have been guilty of inexcusable offences,” which it goes on to describe.

Katharos License
Software so licensed can’t be used for pornography, murder, mass surveillance, theft of private information, or subverting peaceful assembly or the democratic process.

Opinionated Queer License v1.1
Contains an extensive list of prohibitions including using the software for bigotry, abuse of human rights, law enforcement, or big business.

Anti 996 License
It targets the China labor law requiring workers to work 9 a.m. to 9 p.m. six days per week.

Do No Harm License
The Apache License with an added limitation that the software cannot be used by organizations that are involved human rights abuse, environmental destruction, war, or addictive products and services.

Hippocratic License v2.1
Rights are only granted to licensees who comply with human rights principles and laws (as described in the license).

Programming Unity License 10.42
One may only “exercise (their) license” if they follow the software engineering code of ethics and only in countries that support same-sex marriage, allow LGB people to serve in the military, and prohibit sexual orientation discrimination.
 

For entertainment purposes only

Erik McClure’s Bad Licenses
He hosts a collection of “out there” licenses including some of the above. Many of them, though, were created by Erik (or submitted by others) purely for satirical purposes with no intention of actually being used. Examples: the Hot Potato License (copyright is constantly passed to the last committer) and the Passive Aggressive License (one can do anything they want with the software except run it).

Ben Keith’s Collection
Similarly, Ben maintains a long list including his own satirical creations. Two examples are The Fight Club License (we can’t talk about it) and the Schrödinger License (licensed material must be simultaneously observed and not observed).

When humor meets enterprise reality

Licenses like Beerware are often cited as lighthearted examples of open source culture. But even small deviations from standard license language can matter in enterprise environments, especially when obligations become ambiguous or enforceable.

Other licenses go further, introducing conditions that are difficult—or impossible—to interpret consistently. Requirements to use software only for “good,” prohibitions based on subjective ethics, or clauses that restrict usage by certain groups can all raise red flags during audits.

From a legal perspective, ambiguity is risk.
 

Why this matters for software teams

Modern applications are assembled from hundreds—or thousands—of open source components. Without visibility into license terms, organizations may unknowingly introduce software that conflicts with internal policies, customer requirements, or regulatory obligations.

These issues rarely surface early. More often, they appear late in the development life cycle—during audits, acquisitions, or release readiness reviews—when remediation is most expensive.