This is an experiment in writing a little scheme-like lisp. It implements some runtime features like tail call elimination, defmacro-style macros, and first-class continuations, but is lacking many other basic language features. It is mostly intended as a way for me to try out writing a simple garbage collector and continuation-passing style from scratch in C without depending on built-in features of higher-level languages.
An example of some actual llisp code is given in stdlib.llisp where the (extremely minimal) standard library is implemented. The language constructs implemented in C can be found in globals.c.
Although execution won't cause a stack overflow, there is no such guarantee for the parser. It is implemented as a simple recursive descent parser, and will overflow the stack on input that's nested deeply enough. You shouldn't try to use this language for production-quality software since it's slow and idiosyncratic and missing a lot of features, but it's definitely a bad idea to even parse untrusted user input.