Sam Stephenson (http://conio.net/) was gracious enough to take a close look at
cmd.rb's API early on. If you find yourself pleased or impressed with a feature
of cmd.rb it's most likely something that was his idea. He also supplied me
with an excellent example of cmd.rb's usage with his calc.rb that you can find
in the example directory.

Jamis Buck (http://jamis.jamisbuck.org/) who enriched Cmd's domain language
with his suggestion for a 'handle' macro.

Mikael Brockman (http://www.phubuh.org/) 

Scott Barron (http://scott.elitists.net/)