MathMoon is free software and licensed under the GNU GPL. Only the source code is available here. If you are interested in a binary package, I might be able to provide one (possibly for a small fee), depending on your operating system.
The program uses some images. The source code distribution contains
images that have been adapted to this program. You can also download
the original images as I
found them on the Internet. Most of them are in the public domain (but
see the file
IMAGES to be sure).
All versions of MathMoon are available from http://savannah.nongnu.org/download/mathmoon/.
2005-04-04: mathmoon-0.3.1.tar.bz2. A bug fix release containing some minor fixes. The original images are now a separate package.
2005-03-30: mathmoon-0.3.0.tar.bz2. This version introduces some mathematical contents, and is probably the first to be interesting for the end user.
2004-09-24: mathmoon-0.0.1.tar.bz2 contains the program source code. This version is the initial release.