[License-discuss] Fwd: Yet another question about using libraries with different licensed in OSS

[Alex Rousskov]

On 01/18/2017 04:20 AM, Henrik Ingo wrote:

> The only annoying part when mixing two of them together is that you
> must still correctly retain the license for each piece of code. So the
> source code file that was originally BSD licensed must retain the BSD
> license in its header, and likewise for the file that is MIT license.
> You must just be careful not to mix them.

Fortunately, "retaining the license for each piece of code" does not
imply segregating the licensed code on a file level (or any other
specific technical level). The authors did not license "files". Their
licenses say nothing about "headers". The authors licensed their code.
Where you place that licensed code is up to you, and you may mix "code
pieces" as needed.

When dealing with a project containing a complex mixture of simple,
compatible licenses like BSD and MIT, the easiest thing to do is to
acknowledge their existence in one place (e.g., NOTICE or COPYING file),
under a general "this Software contains code licensed under the
following licenses:" header. This will satisfy BSD and MIT license
requirements. Many open source projects do that because tracking
individual license X or author Y "code pieces" for licensing purposes
quickly becomes impractical, has no value for a typical open source
project, and may actually harm development.

I can only imagine one scenario where a centralized disclaimer does not
work well for simple licenses like MIT and BSD: If the projects finds
significant value in eventually removing all code licensed under license
X or by author Y. Such situations are rare exceptions for genuine open
source projects.


HTH,

Alex.