The fontdiff perl utility

Here is an example:

d:\tex\dvii>fontdiff.cmd a b
perl D:\scripts\fontdiff.pl a b
Fonts in a.dvi NOT in b.dvi:
------------------------------
  f:[XX/cmbx10/1000]::1af22256
------------------------------

Fonts in b.dvi NOT in a.dvi:
------------------------------
  f:[XX/cmti10/1000]::fd00273a
  f:[XX/cmsl10/1000]::70ae304a
------------------------------

Fonts in common that have DIFFERENT checksums:
------------------------------
------------------------------
There are a variety of options:
fontdiff.pl 0.02 (23 September 2001)
USAGE: fontdiff [options] dvi_file1 dvi_file2

OPTIONS
-c : ignore checksum when finding font differences
-C : do NOT ignore checksum when finding font differences (DEFAULT)
-n : ignore font number when finding font differences (DEFAULT)
-N : do NOT ignore font number when finding font differences
-s : ignore font scaling when finding font differences
-S : do NOT ignore font scaling when finding font differences
(DEFAULT)
-l : list fonts for each file

Note: if -c is chosen, the checksum difference table will not appear.
Thus, 'fontdiff' (with no options) is equivalent to 'fontdff -C -n -S'