Question on Dual-Licensing Some Code for Phobos

[Shachar Shemesh]

On 30/11/17 21:17, Jack Stouffer wrote:
> I'm starting work on a proposal for stdx.decimal, and one of the 
> clearest implementations to work off of is the Python implementation.
> 
> This however, poses a problem because Python's source is under the PSFL, 
> a BSD-like permissive license. Any derivative work, such as a D 
> conversion, must have the original copyright notice, a copy of the PSFL, 
> as a well as a summary of changes. This is simple enough to do, but the 
> resulting code would be dual-licensed with the PSFL and the BSL 1.0 
> (dual-licensing being relatively common in other OSS projects).
> 
> My question is there any reason this could pose a problem? Could this 
> interfere with something like distribution or company adoption?
> 
> Also note, one of the existing Phobos modules, std.net.isemail, is 
> supposed to be dual-licensed because it's derived from an existing BSD 
> work. But, it's missing the BSD license from the top (and is technically 
> breaking the license because of that).

IANAL

That's not how it works.

Dual licensing means anyone can use the code under one license *or* the 
other. That is not something you can do on your own.

If the PSFL license and the Boost license are *compatible*, then what 
you can do is take the original Python code under the PSFL and convert 
it to D, licensing *your changes* as Boost. The result should look 
something like this:

This code is copyright (C) 2017 Jack Stouffer
Original Python code copyright (original copyright notice)

Python code is licensed under the PSFL

PSFL head goes here.

D code is licensed under the Boost license:

Boost license header goes here