Re: Use GhostScript API instead of forking (issue 548030043 by address@hidden)

[dak]

On 2020/05/03 09:46:56, hahnjo wrote:
> rebase + allow -dgs-api=#f to still fork

I decided to look up the terms of the Affero GPL version 3.  The
relevant differences are:

> Notwithstanding any other provision of this License, if you modify the
Program, your modified version must prominently offer all users
interacting with it remotely through a computer network (if your version
supports such interaction) an opportunity to receive the Corresponding
Source of your version by providing access to the Corresponding Source
from a network server at no charge, through some standard or customary
means of facilitating copying of software. This Corresponding Source
shall include the Corresponding Source for any work covered by version 3
of the GNU General Public License that is incorporated pursuant to the
following paragraph.

Note that we don't modify Ghostscript (I hope).

> Notwithstanding any other provision of this License, you have
permission to link or combine any covered work with a work licensed
under version 3 of the GNU General Public License into a single combined
work, and to convey the resulting work. The terms of this License will
continue to apply to the part which is the covered work, but the work
with which it is combined will remain governed by version 3 of the GNU
General Public License.

That does not sound like LilyPond would get "infected" by the AGPL.  Not
does it sound like any conditions would trigger unless someone modifies
Ghostscript.  Frankly, this almost sounds like the license was written
explicitly in a manner where it would not get in the hair of GhostScript
API users.

However, what this does mean is that we very much should avoid to be
modifying the Ghostscript sources in any manner, including any patches. 
As long as we don't modify Ghostscript, it sounds like we (and, by the
way, Scorio.com) should be free of other obligations (except of course
the normal GPLv3 terms) even when linking with it.

Of course, we should still prominently mention that this binary contains
AGPL parts.  But I think we could link with the GS API by default and
enable it if that makes sense.

https://codereview.appspot.com/548030043/