brid.js (pronounced like "bridges")
is a LISP that uses JSON instead of S-Expressions
implemented in JavaScript

based upon Peter Norvig's lis.py
(Sorry I dropped your ai-class, Peter.)

This was partially inspired by Stuart Halloway's talks
"Simplicity Ain't Easy" and "Radical Simplicity"

But the real story is:
Sometimes I need to use JSON outside of REST
And I've started using a style of
JSON document that looks a lot like S-Expressions.
For example, in json_shape ( https://github.com/jes5199/json_shape ),
I describe JSON datatypes using predicates that look like this:
["array", {"contents": ["number", {"max":255, "min":0} ] } ]
And in the Clojure port, ( https://github.com/jes5199/cljson_shape )
I actually translate that directly into a Clojure S-Expression, like so:
(array {:contents (number, {:max 255 :min 0} ) } )
Which is almost one-to-one, if you blur the distinction
between symbols, keywords, and strings.
So why not actually implement such a LISP?

brid.js currently implements a tiny subset of Scheme and Clojure
It does not yet support macros.
It does not support tail recursion.
Its standard library is woefully incomplete.

I've got a REPL in bridjs.html, also available at http://jes5199.github.com/brid.js/bridjs.html

Example expressions:
["map", ["lambda", ["x"], ["+", "x", 1] ], ["quote", [1, 2, 3]] ]
["reduce", "+", ["quote", [1,2,3,4,5]]]

Released under the MIT license.
Patches welcome.

dedicated to my best friend Jenn
on some sort of anniversary, marking 1 year
29th of November, 2011