qzdoom-gpl/docs/licenses

The original Doom source code was released by id Software under the
Doom Source Code License. See doomlic.txt.

Parts of the voxel code in the software renderer use code from the
BUILD engine by Ken Silverman. Permission has been obtained to use this code
under the terms of the GNU General Public License v3.0. See r_voxel.cpp.

The majority of original code uses a BSD-like lincese. See bsd.txt.

The OpenGL renderer is released under the LGPL v3, except some bits
of code that were inherited from ZDoomGL.

This software is based in part on the work of the Independent JPEG Group.

This software uses the 'zlib' general purpose compression library by
Jean-loup Gailly and Mark Adler.

This software uses the gdtoa package, see gdtoa.txt.

This software uses the snes_spc library, which is covered by the GNU Lesser
General Public License. See lgpl.txt.

This software uses the "Dynamic Universal Music Bibliotheque" library for
MOD music playback. See dumb.txt for original license. The version used,
however, has been heavily modified from its original form and is the same
version used by the foobar2000 component foo_dumb as of mid-2008, found at
http://kode54.foobar2000.org/.