From: Peter Spjuth on
What:
Utilities for comparing stuff.
The working commands are diffFiles, for line by line comparison of
files, and diffLists, for comparing elements of a list.
It is basically an LCS diff algorithm implemented in C on top of Tcl's
API.

Where:
http://github.com/pspjuth/DiffUtilTcl
http://wiki.tcl.tk/26364
Version 0.3 is also in ActiveState's Teapot.

/Peter