Part of the discussion about packaging some of the TikZ answers into a LaTeX package has centred on the issue of licensing the code. Contributions here are licensed under a CC license (see links at the bottom of the page) which isn't the best for software: even the people behind the CC licenses do not recommend its use for software. LaTeX packages are usually licensed under the LPPL (see http://www.latex-project.org/lppl/), but other free licenses such as GNU GPL (see http://www.gnu.org/licenses/gpl.html) are sometimes used. Exactly how the various licenses interact is ... complicated. As the goons memorably quipped,
It's all rather confusing, really.
However, the people who answer questions retain copyright on their material and are therefore free to relicense it as they wish.
In the ensuing discussions, some have felt that the simplest thing to do is to issue a blanket declaration saying that repackaging and relicensing of their code written on this site is allowed. The purpose of this question is to allow people to publicly state what terms their code is released under. Note that this is in addition to the standard SE license terms and is designed to make it easier for people to repackage answers as desired.
There are many open source licenses out there. Some useful links are:
- The list at gnu, including the FSF's beliefs on which are compatible with GPL.
- The list at CTAN, including CTAN's beliefs on which are free.
Here are some comments to bear in mind when choosing how to relicense your code:
- The purpose of this is to make it easier for others to build on your work.
- GPL is probably the most popular for software in general, and LPPL for TeX packages specifically.
- The LPPL and GPL are incompatible.
- It is possible to license code under several licenses, with the choice of license being for the user to decide. Indeed, any declaration here is in addition to the CC-BY-SA license that the site automatically applies.
- If the issue is too confusing, there's always the option of placing the work in to the public domain
Some notes on the licenses:
- An article on why everything should be GPL-compatible: http://www.dwheeler.com/essays/gpl-compatible.html
- There is a separate issue of attribution. Many licenses require that the code be properly (and appropriately) attributed. It is for the user (or repackager) to ensure that their reuse of code is properly compliant with the license in this, and other, ways.
When answering this question, please state the terms under which you agree to your code being reused. Sample statements follow, though you are free to adapt them as required.
Any code of mine that I publish on https://tex.stackexchange.com/ I hereby relicense under the [GPL](http://www.gnu.org/licenses/gpl.html) (version 3 or later) and under the [LPPL](http://www.latex-project.org/lppl/).
Permission to relicense:
Any code of mine that I publish on https://tex.stackexchange.com/ I hereby give permission for it to be used and released under either the [GPL](http://www.gnu.org/licenses/gpl.html) (version 3 or later) or under the [LPPL](http://www.latex-project.org/lppl/).
Any code of mine that I publish on https://tex.stackexchange.com/ I hereby place in the public domain to the extent governable by law. Explicitly, I place it under the [CC0](http://wiki.creativecommons.org/CC0).