A few weeks ago I wondered what it takes to turn a small LISP-1 into a LISP-2. Turns out it takes just a few hours to get most things right, then some days to iron out a few subtleties, and then a couple of weeks to polish it into a piece of art.
MICRO COMMON LISP is a tiny, purely symbolic, microscopic subset of #CommonLISP. It runs in less than 64K bytes of memory, even on #DOS (tiny model) or CP/M. Here it is:
http://t3x.org/mcl/
#CPM#LISP