If you had a Java-capable browser, you could play TransChess here.
Keys "s"=save "l"=load "b"=back once

Ralph Betza 1993. In this co-chess variant, you must move any non-royal unit on a cosquare to another vacant square.

I have not yet implemented the option to plan "illegal" moves which generate cosquares and transportations to get the king out of check.

I have allowed the machine, though not the human player, to forego moving units on cosquares.

This is supposed to be the favorite form of cochess.

Overloader-Restorer Chess

Chess Variants

Meet Ed

These are simple illustrations rather than strong opponents.

Bug reports? -- Thank you! Keep them coming!