SIOF: A Minimal R7RS Scheme Interpreter in One C File

SIOF is a portable R7RS Scheme interpreter built from a single C source file. It boasts no external dependencies beyond standard C libraries, making it incredibly lightweight and easy to compile and run. While supporting key Scheme features like garbage collection, tail recursion, and call/cc, SIOF has limitations including no bignum support, limited Unicode handling, and incomplete R7RS standard compliance. Its core is based on code originally written in #F, with compiler and macro expander components derived from the work of Marc Feeley and Al Petrofsky.