This is a very very simple Lisp (well, OK, more like Scheme) interpreter,
written in the Delphi dialect of Pascal. 

TO COMPILE:

If you actually have Delphi, then I suppose you load up lispi.pas and compile
that beasty.

Otherwise, grab Freepascal (http://www.freepascal.org) and run

fpc -Mdelphi lispi.pas

Then under *nix run 

./lispi

I have rlwrap (http://utopia.knoware.nl/~hlub/uck/rlwrap/) because I'm too lazy
to interface with readline myself, so I run

rlwrap ./lispi

Under Windows it would probably involve double clicking whatever came out of
the compilation.

NOTES:

Iteration is achieved with tail recursion.

There exists a means of adding syntax, in the form of define-macro.

The actual syntactic forms there are pretty thin on the ground, but never mind.