But wait a moment, I looked up the License zandronum was on ( sleepycat
license), and it was FSF approved and compatible with the GNU GPL
http://www.gnu.org/licenses/license-list.html#BerkeleyDB
and this disclamer about the license from zandronum.com proves it:
****************************************************************************************************************************************************************
New code in Zandronum is released under a 4-clause license based on the
OSI-approved and GPL-compatible Sleepycat License, with the addition of the
"No Endorsement" clause from the 3-clause New BSD License.
Practically, this means that Zandronum's source code is safe to use in either
GPL or Doom Source License/Raven Source License/etc. source ports as long as
the terms of the Zandronum license are satisfied.
The Zandronum license only covers Zandronum-specific code. Some source files
contain additional notices of original copyright by their contributors.
See ZDoom license page for more details on other licenses used within
Zandronum.
****************************************************************************************************************************************************************
