Guile is an implementation of the Scheme programming language. In addition to supporting the R5RS Scheme standard, a large subset of R6RS, and many SRFIs, Guile includes full access to POSIX system calls, networking support, multiple threads, dynamic linking, and a foreign function call interface. Guile can run interactively, as a script interpreter, and as a Scheme compiler to VM bytecode suitable for stand-alone applications. It is also packaged as a library so that applications can easily incorporate a complete Scheme interpreter/VM.