lisp500
A mostly-joking implementation of a lisp in just 500 lines of C.
The original public posting of this has been lost, so I searched for it in my own archives and am reposting it. This only really exists because of oneupmanship and a poorly-thought-out claim that you can implement lisp in 500 lines of C. Well, you can, but it's not a very useful lisp. But then you can have an init file (in lisp) fixing some of the problems in usefulness.
compilation
gcc -m32 -o lisp500 lisp500.c
or
clang -m32 -o lisp500 lisp500.c
For linux add -lm -ldl
(It's really nothing but assumptions that the word size is 32 bits so -m32 is required.)
running
./lisp500 init500.lisp
You can also run just ./lisp500 and use the barebones version.