Posted by maqifrnswa on Jan 25, 2012; 2:25pm
URL: https://forum.librecad.org/Different-versions-of-GPL-tp5429963p5430297.html

On Wed, Jan 25, 2012 at 6:33 AM, Borneq [via LibreCAD]
<[hidden email]> wrote:
> dxflib of RibbonSoft is under GNU General Public License version 2, LibreDWG
> is under GNU General Public License version 3 (or at you option any later
> version). How link code under two version of GPL?

We've been talking with the FSF on several occasions about this as
well as the libreDWG developers. I happened to talk to one of the FSF
licensing expert volunteers a couple weeks ago. Rallaz and dxli are
totally correct. QCAD is GPLv2 only. That causes lots of problems when
interfacing with other libraries (such as libreDWG which is GPLv3+).
The only way to upgrade QCAD is to totally remove the original code
and replace it with GPLv2+. We're allowed to, and have been, licensing
all patches as GPLv2+. Eventually it is possible that we would have
totally rewritten the QCAD code with entirely new stuff. If that
happens, we can re-license as GPLv2+.

However, the developers of librwdxf (GPLv2+) plan on writing a new
application which converts .dxf into .dwg. LibreCAD can call that
application from within LibreCAD after librecad saves a .dxf file
using libredxf. That is a legal way to use libredwg since librecad
would never link to libredwg, but fork and run a conversion utility.