CC license on library code, (L)GPL incompatible

Hi all (and, perhaps specifically, Ben),

The Pololu libraries, while wonderful, are licensed under a CC BY-SA v3.0 license. I was looking to use some of the code in these libraries in an LGPL-licensed project, and I cannot. Specifically, I and my colleagues work on tools to support parallel programming on a variety of platforms, including the AVR family of devices (

The Creative Commons website is rather clear on the use of their licenses for code: they strongly recommend you do not: … oftware.3F

This weblog post from 2006 has a very nice summary of why CC licenses are bad for code: … e-for-code

Yet more good commentary can be found here (given some of the sources quoted, it may be even more relevant):

I do not need to use your code, truly, but it would have saved me some time to be able to edit, reshape, and simply credit where the code came from. I cannot, however. The CC license on code has too many incompatibilities with the GPL, and therefore, your code cannot actually be built upon in a free piece of software. It may be we could link against the binaries, but even then the licensing on your header files is CC-BY-SA… so, again, we could not (truly) leverage your code in our project.

Please note: I am not a lawyer. Sadly, licensing must turn any developer into a bit of an armchair lawyer, just so they don’t “do the wrong thing.” My hope is that, by pointing this out, there might be some discussion and, ideally, a change of license on your codebase to something that is actually appropriate for free and open sharing of code.

Many thanks,


Thanks for the detailed feedback on the license. We are aware that the CC licenses are (strongly!) not recommended for use with code. As far as we can tell, there are only two issues:

  1. No GPL compatibility.
  2. Not designed for code; unclear on issues of compiled vs. source code.

As for #1, we do not necessarily want our code to be GPL compatible. We also do not really understand the difference between the CC BY-SA and the X11 Licence in this respect - would the X11 work much better for you for some reason?

Issue #2 also does not bother us much, because we expect our customers to only use the Pololu AVR Library for programming their robots - not for larger software projects. We want people to feel free to pass around copies of our code at their robot clubs, make modifications to the library and post the changes on their blogs, and so on, but incorporating our code into a separate software library is very different and not something we ever planned to cover with our license.

We have taken a look at and cannot figure out what it is really about, we do not know how our code could be useful to you, and we do not know how allowing you to use our code would benefit our customers, but we would certainly be interested to hear more from you on any of these points. For example, are you interested in supporting Orangutans?