The following notice applies to the files scheme1.gif and images/active/stump.jpg:

Copyright 1996 Igor Chudov. This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.

All the other images in this directory hierarchy do not cross the threshold of originality and can therefore be presumed to be in the public domain.