Inside: Racket C API

This manual describes the C interface of Racket’s runtime system for the 3m and CGC variants of Racket (but not the CS variant; see Racket Virtual Machine Implementations). The C interface is relevant primarily when interacting with foreign libraries as described in The Racket Foreign Interface; even though interactions with foreign code are constructed in pure Racket using the ffi/unsafe module, many details of representations, memory management, and concurrency are described here. This manual also describes embedding the Racket run-time system in larger programs and extending Racket directly with C-implemented libraries.