Guile is an implementation of the Scheme programming language, with support for many SRFIs, packaged for use in a wide variety of environments. In addition to implementing the R5RS Scheme standard, Guile includes a module system, full access to POSIX system calls, networking support, multiple threads, dynamic linking, a foreign function call interface, and powerful string processing. Guile can run interactively, as a script interpreter, and as a Scheme compiler to VM bytecode.