Recommend a license for third-party libraries in library tutorial

[Coding-Badly]

Please unify the libraries under a single license. Currently, at least six different licenses are used.

Please also recommend a license for third-party libraries.

[matthijskooijman]

I'm not sure this is possible - a lot of the libraries have been originally written by third parties and/or include code and later contributions from others. You can't just change the license on code unless all authors agree, and contacting all authors is a fairly big effort...

[Coding-Badly]

The flip side of the argument is that the following cannot be legally redistributed by anyone except the original author because there is no license agreement...

https://github.com/arduino/Arduino/blob/master/libraries/Ethernet/Dhcp.h
https://github.com/arduino/Arduino/blob/master/libraries/Ethernet/Ethernet.h
https://github.com/arduino/Arduino/blob/master/libraries/Ethernet/EthernetClient.h
https://github.com/arduino/Arduino/blob/master/libraries/Ethernet/EthernetServer.h

Essentially, the Arduino folks, and everyone else who uses those files, are violating the copyright law.

Of course it is possible for the Arduino folks to recommend a license for third-party libraries. That alone would be a huge benefit.

[matthijskooijman]

Code without a license is definately a problem that needs to be fixed, agreed. However, arduino/Arduino#1117 and arduino/Arduino#1847 are already tracking this issue.

As for recommending a license, that's definately a good idea. In the library spec discussion a while ago, I proposed a text to at least point out to people that they need some license:

https://groups.google.com/a/arduino.cc/d/msg/developers/R3VCal5FVa0/XgZ1LBvabhYJ

In another discussion, the LGPL license was indicated as less-than-ideal, but no real alternative was settled on yet.

https://groups.google.com/a/arduino.cc/forum/#!topic/developers/QeDMRF__qXs

Perhaps it makes sense to start up this discussion again on the developers list?

[per1234]

Considering that the Arduino software doesn't currently have any sort of library license detection/enforcement/etc. system, I don't think the specification would be an appropriate place for this. It would make more sense to put it in another document with a different focus, perhaps here:

https://docs.arduino.cc/learn/contributions/arduino-creating-library-guide

There is now an official tool for encouraging best practices in addition to enforcing specification compliance: Arduino Lint. Arduino Lint does have a rule that checks for the presence of one of the recognized license files GitHub's automated license detection feature uses. This is only a warning when Arduino Lint is in the "specification" or "permissive" compliance modes, but it's upgraded to an error when used in "strict" compliance mode. It doesn't currently parse the contents of the file to determine the license type as GitHub's system does with the licensee Ruby gem. It would be interesting to try to add that capability to Arduino Lint eventually in a rule that fails if the license type was not recognized.

[per1234]

I mentioned Arduino Lint's license file check above. The new Library Manager system takes another step in encouraging licence documentation in Arduino libraries by running Arduino Lint on all libraries submitted to the Arduino Library Manager index, and on every release of the libraries in the index.

At the compliance setting used by the Library Manager system, lack of a licence file only results in a warning, but this warning is displayed during the submission process and also in the indexer logs. I believe this approach will result in improvements to the overall level of license documentation in the Arduino ecosystem without requiring a huge effort or causing a lot of disruption.

[jcarolinares]

Hello, @jacobhylen this issue is from 2014 and it is not fully related with docs

Whatever actions may be taken into consideration they are not related with this repository.

I suggest @jacobhylen to close this issue