This software contains data files from the rikaichan 1.04 distribution.
The files in question are kanji.dat and radicals.dat.

The original copyright statement is here:

KANJIDIC2
Copyright (C) 2007 The Electronic Dictionary Research and Development Group
http://www.csse.monash.edu.au/~jwb/kanjidic2/

Basically, rikaichan is using the kanjidic and radkfiles from the Electronic
Dictionary Research and Development Group.  However, they have changed
the format and added quite a few entries.  It is much easier to parse
and more useful.  Also, they are using UTF characters instead of EUC
characters meaning that many more of the proper radicals can be shown.

In their own distribution they don't mention their own changes, but they
should be given a lot of credit for doing this work.