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Round Robin Licensenew name, new terms, same great idea

Very pleased to announce that the search for a friendlier, memorable name for the former API Copyleft has come to an end. Have a quick look through the new Round Robin Software License.

I’ll have a website as soon as I get to it. I’m also wee black bird with a big red paunch and a twig in its mouth for a mascot.

License follows, plus comments. The text weighs in well shy of six hundred words, not one of which is “coronavirus”.

Round Robin Software License

Version 1.0.0-pre.2

1.0.0 will come very shortly. I’m giving myself twenty four hours or so to step away and come back, and of course to take any feedback from folks reading the blog.


This license allows you to use and share this software for free. You can share and license your applications how you like, but you have to share changes, additions, and other software that builds on this software alike.

Those of you who read too many of my blog posts will notices this is further in line with Prosperity and Parity, the licenses from License Zero.


In order to receive this license, you have to agree to its rules. Those rules are both obligations under that agreement and conditions to your license. Don’t do anything with this software that triggers a rule you can’t or won’t follow.

Contractions? In a license? That’s right, folks!


Make sure everyone who gets a copy of any part of this software from you, with or without changes, also gets the text of this license or a link to

Like some other licenses I’ve done, this one allows notice by permalink, without copies of the license terms.

This is nice for users, and usually makes sense when the license is a fixed form without any blanks to fill in. Both Parity and Prosperity include blanks for identifying the licensor, but since Round Robin doesn’t, a reference link is fine.


With two exceptions, Prototypes and Applications, contribute all changes and additions you make to this software, as well as all software that invokes this software’s functionality. When in doubt, contribute.

Round Robin incorporates the latest thinking in Parity 7, including Parity’s prototypes exception. That exception serves a somewhat different function here, but the structure is much the same.


You don’t have to contribute any change, addition, or other software that meets all these criteria:

  1. You don’t use it for more than thirty days.

  2. You don’t share it outside the team developing it, other than for non-production user testing.

  3. You don’t use it for anyone outside the team developing it.

Analogous to a free trial, which Prosperity builds in. Enough to kick the tires without opening a massive loophole.


You don’t have to contribute any software that only invokes this software’s functionality through the interfaces this software exposes, unless it exposes so much of this software’s interfaces or functionality to users, programmers, or other software that it becomes a practical substitute for this software. Interfaces exposed by this software include all the interfaces this software provides users, programmers, or other software to invoke its functionality, such as command line, graphical, application programming, remote procedure call, and inter-process communication interfaces.

The heart of the license. This language was already thoroughly refined in API Copyleft before.


To contribute software:

  1. Publish all source code for the software in the preferred form for making changes through a freely accessible distribution system widely used for similar source code so the contributor and others can find and copy it.

  2. Make sure every part of the source code is available under this license, the Blue Oak Model License 1.0.0, the BSD-2-Clause Plus Patent License, or terms with substantially the same legal effect as Copyright, Patent, and Reliability, and optionally a rule like Notices, a disclaimer like No Liability, or both, but no other terms.

  3. Take these steps within thirty days.

  4. Note that this license does not allow you to change the license terms for this software. You must follow Notices.

Much in line with Parity 7. But note the slightly stronger rule on choice of license. You can choose Round Robin itself for your work, or you can choose a permissive license, but not any license along that spectrum.


You’re excused for unknowingly breaking Copyleft if you contribute as required, or stop doing anything requiring this license, within thirty days of learning you broke the rule. You’re excused for unknowingly breaking Notices if you take all practical steps to comply within thirty days of learning you broke the rule.

Straight out of Parity 7.

Each contributor licenses you to do everything with this software that would otherwise infringe that contributor’s copyright in it.

Short, sweet, modern total copyright license.


Each contributor licenses you to do everything with this software that would otherwise infringe any patent claims they can license or become able to license.

Note there isn’t any patent defensive termination provisions. That’s more in line with Blue Oak.


No contributor can revoke this license.

More echoes of Blue Oak.

No Liability

As far as the law allows, this software comes as is, without any warranty or condition, and no contributor will be liable to anyone for any damages related to this software or this license, under any kind of legal claim.


Your thoughts and feedback are always welcome by e-mail.

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