I stumbled upon EchoLisp [1] on rosettacode.org, and I couldn't find out much about who created it, and if it is available for download or just hosted via the site only.
A lot of Rosetta Code tasks have been completed in it already.
It has great documents and examples with some interesting graphics and a lot of math.
[1] http://www.echolalie.org/echolisp/