Numdiff
Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 - Ivano Primi <ivprimi(at)libero(dot)it>
(Ivano Primi <ivprimi(at)libero(dot)it> is also the author of the program)

Note:

Numdiff includes source code from 

*  GNU BC 1.06, Copyright (C) 1991, 1992, 1993, 1994, 1997, 2000 
   Free Software Foundation, Inc.

*  GNU C Library, Copyright (C) 1989-1994,1996-1999,2001,2003,2004
   Free Software Foundation, Inc.

and source code from

GNU DIFF, Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1998, 2001, 2002
Free Software Foundation, Inc.