This is Turing equivalent, however in its present form it only reduces an expression to a normal form and stops there. I'll enhance it later to emulate some "side effects" such as print and read.

I use this technology when I need to embed a lightweight functional programming system into an existing program, written in C, Perl, or whatever.

I encourage you to push the button labeled "Evaluate". I think it's fun to push that button, but surprisingly few people do.