A graphical diff program

 Fldiff is a graphical diff program that shows the differences between
 two files/directories, or a file/directory and a CVS or Subversion repository.
 It is inspired by xdiff (Motif-based) and xxdiff (Qt-based), whose choice of
 GUI toolkit has hampered their portability to many of the systems.
 .
 Fldiff uses the Fast Light Toolkit (FLTK) and has been tested on AIX, IRIX,
 Linux, MacOS X, and Solaris, and should also run on Windows.