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Diving deep into wild and wacky open source licenses

Most open source components are licensed under common licenses, but dozens of interesting or just weird open source licenses remain on the lunatic fringe.

Diving deep into wild and wacky open source licenses

When many seasoned attorneys familiar with commercial software licenses first encounter the GPL, the copyleft terms seem pretty strange. But the GPL is far from the weirdest license out there. The GPL remains the most popular license and the choice for millions of open source components available today. But there is a long, long tail of over 2,500 licenses in the Black Duck KnowledgeBase—many of which are one-offs. While the GPL has come to be reasonably well-understood, a number of interesting licenses on the lunatic fringe will surprise and perhaps amuse.

Between the blankety-blank license lines

Several unusual licenses flout the concept of a license altogether. Between the lines, they seem to say, “OK, we’ll play along, but we don’t need no $#(&@ing license.” A few of this class, in fact, employ similarly colorful language to make that point. Best known of these is the WTFPL, the license that says you can do what the [heck] you want. It’s pretty clearly intended to be the most permissive license in the world. However, some companies, notably Google, find the grant of rights too vague and prohibit use of software under that license.

Another along these lines is the No Problem Bugroff License. Here’s the entirety of the text: “Sure, No problem. Don’t worry, be happy. Now bugger off.” And then there’s the DBAD Public License, which emerged last year. The author actually pays homage to the WTFPL and positions the DBAD between the wide-open WTFPL and the legal protections of more traditional open source licenses. The spirit of the license is that users of the software should just do the right thing—don’t be a [kind of person who would not respect the intellectual property rights of others]—but it states the concept much more colorfully.

Out-there license obligations

Another class of interesting open source licenses specify unusual obligations and/or alternative ways to meet obligations of more standard licenses. Best known of these is the Beerware License (on its 42nd revision!). It requires that the notice be retained and suggests that if users like the software, they buy the author a beer. 

The Chicken Dance License is GPL-like, but as an alternative to distributing source code with binaries, it gives the distributor the option to post a video of employees doing the Chicken Dance to social media sites. Also, inexplicably, it restricts any employee from uttering the word “gazorninplat” in public. Andrew Harris, the author of the license, pushed for approval with the Open Source Initiative. The OSI was mildly amused but, in a brief discussion thread, politely declined on the basis that the license did not meet their criteria.

Liabilities, music, and guitars?

Many of these funny-ish licenses are tongue-in-cheek. I recently came across a freeware license that has a rather extensive liability disclaimer: “If this program accidentaly [sic] screws up and destroys data on your PC, electrocutes you, makes your monitor explode in your face … causes secret agencies to come after you, makes you believe you got maggots crawling under your skin.” You get the idea.

In an unnamed license for some code on CodeForge, George Yohng, a developer and talented pianist, requires his licensees to experience the entirety of a very soothing music video of his creation: “You agree to go to and listen completely (without skips) to the very
first track on the list.” In my opinion, it’s worth listening to even if you don’t use his software.

And continuing the music theme, an open source attorney I know came across a license that, for redistribution, required you to send the copyright holder a Fender Stratocaster guitar. He and his engineering team, after they discovered some code under that license, determined that was a much cheaper alternative than re-engineering their product. Thus, the company met its obligation and the developer got himself a new guitar.

Tweaking licenses for good … or evil

A number of licenses tweak the language of a standard license. Not a good idea, for a bunch of reasons. A well-known example I blogged about recently is the JSON License. That license is BSD-like, but becomes problematic with the addition of these nine words: “The Software shall be used for Good, not Evil.”

Finally, speak of devil, the big prize for weirdest license out there goes to the Death and Repudiation License. The text is fairly elaborate but is pretty much summed up in the first line: “This software may not be used directly by any living being.” In fairness, the SYCK parser kit under this license is dual-licensed with a substantially more permissive one. However, in a final show of weirdness, you may note that while the title of the alternative license reads “BSD License,” the text that follows is actually that of the MIT License!

This is all meant to be entertaining, but there is a point: A plethora of licenses exist for software freely available on the internet. Many are benign, but many deserve attention lest you find yourself dancing on YouTube or suffering death and repudiation. Please share any weird licenses you’ve run across—I’d love to hear about them.

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Phil Odence

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Phil Odence

Phil Odence

Phil is the general manager of Synopsys’s Black Duck Audit business auditing the composition, security and quality of software for companies on both sides of M&A transactions. He focuses on software due diligence best practices and the M&A market. He also works closely with the company’s law firm partners and the open source community and is a frequent speaker on open source management and M&A. Phil chairs the Linux Foundation's Software Package Data Exchange (SPDX) working group which created an ISO standard for Software Bills of Materials (SBOMs). With decades of software industry experience, Phil held senior management positions at Hammer/Empirix and High Performance Systems, a startup in computer simulation modeling. He began his career in marketing and sales with Teradyne's electronic design and test automation (EDA) software group. He’s also written a book on fly fishing. Phil has an AB and an MS in engineering from Dartmouth College.

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