UPX and licensing
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?
upx-ucl is in main - will this have to change? Also, at least the e3
package uses upx to compress its binary already... this would also
have to change.
Now, there is yet another exception for GPL-compatible programs,
saying the modification restrictions don't apply. Can one argue that
this is simply dual-licensing? Or a special usage restriction ("you
may only compress GPL-compatable data with UPX" sounds like "you may
only use <certain data> with <foo program>")?
Reply to: