For the files 

dlr-grid.png
dlr-splash.png
dlr-subplot-add.png
dlr-subplot-remove.png

the following holds:

Copyright (C) 2011-2012 German Aerospace Center DLR
(Deutsches Zentrum fuer Luft- und Raumfahrt e.V.), 
Institute of System Dynamics and Control
All rights reserved.

The above files are part of PySimulator.

PySimulator is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

PySimulator is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License
along with PySimulator. If not, see www.gnu.org/licenses.