MIT/GNU Scheme

MIT/GNU Scheme is an implementation and dialect of the Scheme language, itself a dialect of Lisp, first released in 1986 at the Massachusetts Institute of Technology by Guy Lewis Steele Jr. and Gerald Jay Sussman. It was published as free software before the Free Software Foundation, the GNU project and the GPL existed, and it is now part of the GNU Project, available under version 2 or later of the GNU General Public License. The system can produce native binaries for the x86 processor family in 32 and 64 bit forms and supports the R7RS-small standard. It offers a rich runtime library, a source level debugger, a native code compiler and a built-in Emacs-like editor called Edwin. The textbooks Structure and Interpretation of Computer Programs and Structure and Interpretation of Classical Mechanics include software that runs on it. Its interpreter prints a Latin farewell, moriturus te saluto, when the user exits.