Thread: GMP with GWNUM support? View Single Post
2021-09-22, 04:09   #7
Happy5214

"Alexander"
Nov 2008
The Alamo City

75810 Posts

Quote:
 Originally Posted by axn Why? IIUC, a closed source s/w using a GPL library needs to open up the closed source, but reverse (an open source s/w incorporating a closed source library) imposes no such restriction. So I don't understand why the binaries could not be redistributed.
In order to distribute a GMP-ECM + gwnum binary, the whole thing would need to be licensable under the GPL. The Mersenne prime prize distribution rules in the gwnum license (even though completely irrelevant for factoring) add an extra restriction on use that isn't permitted under the GPL, thus preventing the gwnum part of the code from being distributed under that license.

And if you don't believe me, here are lines 897-903 from my (unmodified) SVN copy of main.c from GMP-ECM:
Code:
#ifdef HAVE_GWNUM
#ifdef gwnum_is_gpl
if (! gwnum_is_gpl ())
#endif
printf ("Due to incompatible licenses, this binary file must not "
"be distributed.\n");
#endif

Last fiddled with by Happy5214 on 2021-09-22 at 04:09