The binaries and installer are avilable for Windows only, but the
source code is public domain, and people have reported success
compiling it on Mono.
Cat is a functional stack-based language with an optional type system.
For more information see
* the Cat home page - http://www.cat-language.com
* the wikipedia article - http://en.wikipedia.org/wiki/Cat_programming_language
Cheers,
Christopher Diggins