lisp for scripting/extensions/plugins

which is the best one?

I'm starting a project which requires a bit of low-level programming (and I prefer to be able to deliver it as a self-contained binaries, without the user having to install any sort of lisp runtime) but I've grown used to s-expression syntax so it would be easier for me to implement most of the higher-level logic in something with a lot of parentheses. I'm thinking of writing a C program which consists mostly of a library of low-level functions and a main() that simply loads and executes some lisp scripts. I know Guile Scheme can do that but it's a GNU project so it might suck. what are the alternatives?

>>8
How can 30 bit integers even exist without a type system? I mean unless you're using a CDC 6600 or something, that's not consistent with any machine's word size. 8, 32, and 64 bits are the "natural" sizes for modern computers.