Schemy Lisp En DOS

SLED (Schemy Lisp en DOS) is a lightweight Scheme-inspired LISP interpreter designed to run on DOS and DOS emulators, featuring tail-call optimization, lexical scoping, and garbage collection in just ~1.1K lines of C89 code. The interpreter supports 8 special forms and 21 built-in functions with an 11K executable size, and is released as open-source software. It uses a dual data-type system of pairs and atoms (symbols, closures, and special symbols) to implement LISP functionality in 16-bit real mode.