MIT/GNU Scheme

MIT/GNU Scheme is an implementation of the Scheme programming language, providing an interpreter, compiler, source-code debugger, integrated Emacs-like editor, and a large runtime library. MIT/GNU Scheme is best suited to programming large applications with a rapid development cycle.

Release status and future plans

Current releases
Stable
9.1.1

The releases provide binaries that run on i386 and x86-64 machines under the following operating systems: GNU/Linux, OS X, and Windows. We additionally provide binaries for selected other architectures and systems, depending on the hardware and software that is available to us. We no longer support OS/2, DOS, or Windows systems prior to XP.

Recent release notes are here.

In the future, we plan to deploy a new portable virtual machine and implement a module system. We also plan to finish support for R5RS, but we will not be providing support for R6RS. Other potential projects can be found on the tasks page.

Download

MIT/GNU Scheme is available in binary form for a variety of systems. Note that most problems unpacking or installing this software are due to corrupted downloads, so please check the downloaded file for a correct MD5 checksum before submitting a bug report. Each distribution below has its own list of MD5 checksums.

Stable release 9.1.1
File	Arch	Instructions	Notes
Unix binary	i386	unix installation
Unix binary	x86-64	unix installation
OS X binary	i386		Compiled on OS X 10.6.
OS X binary	x86-64		Compiled on OS X 10.6.
Windows binary	i386	Windows installation	Compiled on Windows 7 using Open Watcom C/C++ 1.9.
Portable C	(any)	how to build	For use on any unix system.
Source (.tar.gz)			For unix systems; uses linefeeds as line delimiters.
Change log
MD5 checksums

Older versions can be downloaded here.

Code for running MIT/GNU Scheme under GNU Emacs is here (or byte-compiled); this has been tested on GNU Emacs versions 20.7 and 21.1, and should replace the file of the same name included with GNU Emacs; it won't work with GNU Emacs 19 or earlier. This doesn't work on Windows or OS/2.

Note that you cannot build a working system from the source unless you have a working MIT/GNU Scheme compiler to do the compilation. (This doesn't apply to the portable C source, which requires only a C compiler.) This means that if the above binaries don't work on your system, it is pointless to try building a custom set of binaries from the source code.

Documentation

Documentation for MIT/GNU Scheme is available online, as is documentation for most GNU software. The MIT/GNU Scheme documentation is available in HTML and PDF formats:

Core documentation:
HTML	PDF	MIT/GNU Scheme Reference
HTML	PDF	MIT/GNU Scheme User's Manual
HTML	PDF	The SOS Reference Manual
HTML	PDF	IMAIL User's Manual
Supported SRFIs:
HTML		0: `cond-expand`
HTML		1: List library
HTML		2: `and-let*`
HTML		6: Basic string ports
HTML		8: `receive`
HTML		9: Defining record types
HTML		23: Error reporting mechanism
HTML		27: Sources of random bits
HTML		30: Nested multi-line comments
HTML		62: S-expression comments
HTML		69: Basic hash tables

Contact us

Please report bugs using the bug-tracking system.
We can be contacted on the mit-scheme-devel mailing list.
New releases of MIT/GNU Scheme are announced on the mit-scheme-announce mailing list.

Our more general Scheme page is http://swiss.csail.mit.edu/projects/scheme/.
Older releases can be found at http://swiss.csail.mit.edu/ftpdir/mit-scheme/.

Getting involved

Development of MIT/GNU Scheme, and GNU in general, is a volunteer effort, and you can contribute. For information, please read How to help GNU. If you'd like to get involved, it's a good idea to join the discussion mailing list (see above).

Development: For development sources, bug and patch trackers, and other information, please see the project page at Savannah.
Maintainer: MIT/GNU Scheme is currently being maintained by Chris Hanson. Please use the mailing lists for contact.

Licensing

MIT/GNU Scheme is free software; you can redistribute it and/or modify it under the terms of the GPL as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.