Re: UPX and licensing

[cjw44@flatline.org.uk (Colin Watson)]

Aaron Lehmann <aaronl@vitelus.com> wrote:
>Previously proposals were discussed to encourage widespread use of
>upx. I have found a licensing issue which I think raises a vaild
>objection to this.
>
>From http://wildsau.idv.uni-linz.ac.at/mfx/upx-license.html:
>
>SPECIAL EXCEPTION FOR COMPRESSED EXECUTABLES
>============================================
>
>   The stub which is imbedded in each UPX compressed program is part
>   of UPX and UCL, and contains code that is under our copyright. The
>   terms of the GNU General Public License still apply as compressing
>   a program is a special form of linking with our stub.
>
>   Hereby Markus F.X.J. Oberhumer and Laszlo Molnar grant you special
>   permission to freely use and distribute all UPX compressed programs
>   (including commercial ones), subject to the following restrictions:
>
>   1. You must compress your program with a completely unmodified UPX
>      version; either with our precompiled version, or (at your option)
>      with a self compiled version of the unmodified UPX sources as
>      distributed by us.
>   2. This also implies that the UPX stub must be completely unmodfied, i.e.
>      the stub imbedded in your compressed program must be byte-identical
>      to the stub that is produced by the official unmodified UPX version.
>   3. The decompressor and any other code from the stub must exclusively get
>      used by the unmodified UPX stub for decompressing your program at
>      program startup. No portion of the stub may get read, copied,
>      called or otherwise get used or accessed by your program.
>
>
>Can we say non-free?

No. That restriction is part of an exception to the GPL: it applies only
when you can't use the freedoms granted by the GPL due to your program
not being GPL-compatible. Thus it's GPL plus additional freedoms - the
fact that these additional freedoms granted by the authors aren't very
free is irrelevant.

In the same vein, it's fine for somebody to say "licensed under the GPL;
if you want to incorporate this into non-GPL-compatible software, you'll
have to contact me and ask for permission", where getting that
permission sometimes involves paying the author money or whatever. A
number of people do this. In fact, see GPL section 10:

    10. If you wish to incorporate parts of the Program into other free
  programs whose distribution conditions are different, write to the author
  to ask for permission.

-- 
Colin Watson                                     [cjw44@flatline.org.uk]