[Cbc] Licensing question

[Ted Ralphs]

Hi all,

We are pretty careful with licensing in general. No source from any of the
third-party dependencies are included in any repo within the "coin-or"
Github organization. All projects in the Optimization Suite are entirely
licensed under the EPL. We use the term "Third Party" specifically to mean
software that may be under a different license and/or copyright and that we
therefore do not redistribute ourselves. We do link to available
third-party libraries when they are already present on the user's machine.
For the most part, it is up to the user to be aware of this.

There are separate projects within the "coin-or-tools" Github organization
that provide convenience scripts for downloading and building the source
for some of these third-party dependencies. If you use the convenience
scripts, it is up to you to be aware of the licenses of the downloaded
code. If you use the coinbrew script to fetch a project and its
dependencies, some of these convenience scripts may be run automatically.
Currently, coinbrew does download third-party sources by default. I'm
slowly rolling out a more nuanced dependency specification system that will
categorize third-party packages as "optional" or "recommended" and will not
download optional packages by default. If coinbrew downloads and builds any
third-party codes automatically, you may end up with some of these
dependencies as part of your self-built binary.

You can prevent download of any third party source code by coinbrew by
adding the argument "--no-third-party", but this will not prevent the
configure script from finding certain libraries that are already installed
on your system and linking to them. That should not be an issue unless you
build and redistribute a static executable, which could then possibly
include parts of the dependent libraries. To prevent this, you would need
to use the appropriate arguments to the configure scripts to suppress use
of particular libraries.  If you are building with shared libraries, then
it is easy to verify with "ldd" what libraries are being linked to,
including both those that are present on the system, e.g., were installed
using a package manager, and those that were built using our wrappers.

As for the distributed binaries, the answer may vary, depending on the
specific version and platform. We've been evolving our recipe over time
according to feedback. For non-static binaries, it's easy to check what
exactly is distributed by checking the contents of the archive after
downloading (though again, there is a chance the code might use a shared
library already installed on your system under Linux, for example). For
static binaries, you would need to check the recipe used to generate the
binary, which would be in either the travis.yml or appveyor.yml
configuration files for Linux/OS X and Windows, respectively.

Sorry for the somewhat convoluted answer, but hopefully, this gives you all
the information you need. Hope this helps and feel free to follow up with
any further questions.

Cheers,

Ted

On Mon, Nov 16, 2020 at 2:11 PM Jan-Willem Goossens <jhmgoossens at hotmail.com>
wrote:

> Dear all,
>
>
>
> Sorry for the partial email earlier.
>
>
>
> In short: Is it correct that none of non-EPL-licensed optional components
> (GLPK, etc.) are included in the source repo of CBC and related
> dependencies?
>
>
>
> I build CBC and its dependencies (Cbc, Clp, Cgl, Osi, CoinUtils,
> BuildTools) from the master branch of their repos.
>
> These all mention EPL v2 as license in their root folder’s LICENSE file.
>
>
>
> However, optional components exist such as GLPK, GNU Readline, GNU
> History, AMPL Solver Library (ASL), BLAS and LAPAC (etc.) that use
> different licenses, and that I therefore want to avoid.
>
> Maybe a silly question, but such components are _*not*_ in the normal
> repos (like https://github.com/coin-or/cbc), or are they?
>
> And as a consequence, these optional components are not in my self-built
> CBC.
>
>
>
> Thank you for your help.
>
>
>
> Jan-Willem
>
>
>
>
> _______________________________________________
> Cbc mailing list
> Cbc at list.coin-or.org
> https://list.coin-or.org/mailman/listinfo/cbc
>


-- 
Dr. Ted Ralphs
Professor, Industrial and Systems Engineering
Lehigh University
(610) 628-1280
ted 'at' lehigh 'dot' edu
coral.ie.lehigh.edu/~ted
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