MIT Scheme Release 7.5

This is the home page for MIT Scheme Release 7.5.
The main home page for MIT Scheme is
The information on this page is also available via FTP at
We can be contacted at
New versions of this software are announced on the info-cscheme mailing list.

Release 7.5 is for x86 (Intel Architecture 32) machines only. We provide versions that run under the following operating systems: GNU/Linux, FreeBSD, IBM OS/2, and Microsoft Windows (95, 98, and NT). We no longer support DOS or Windows 3.x.

Releases 7.4 and 7.3 support other architectures and operating systems. They can be found at and respectively, or at and if you prefer to use FTP.

MIT Scheme is free software. This means that you may copy and modify this software, and redistribute either the original software or a modified version. With this release, MIT Scheme is licensed under the GNU General Public License.

  • Release status
  • Documentation
  • Download
  • Future Plans

  • Release status


    Documentation for MIT Scheme is available online:
    MIT Scheme Reference HTML PDF
    MIT Scheme User's Manual HTML PDF
    The SOS Reference Manual HTML PDF
    IMAIL User's Manual HTML PDF
    Macros in MIT Scheme (not hygenic) Text

    Alternatively, you can download the documentation in a variety of formats:
    Postscript gzipped tar ZIP
    PDF gzipped tar ZIP
    HTML gzipped tar ZIP
    Emacs Info gzipped tar ZIP


    MIT Scheme 7.5 is available in binary form for a variety of systems. MD5 checksums for all of the files on this page are here; they were created with the md5sum program. (A version of md5sum compiled for Microsoft Windows systems is here.) 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.

    File Instructions Notes
    GNU/Linux binary unix installation Compiled on Debian GNU/Linux 2.2.
    Debian package (i386) Compiled on Debian GNU/Linux 2.2.
    FreeBSD binary unix installation Compiled on FreeBSD 3.3-RELEASE.
    Windows binary Windows installation Compiled on Windows 2000 using Watcom C/C++ 11.0a.
    OS/2 binary OS/2 installation Compiled on OS/2 Warp 4.0 using IBM VisualAge C++ 3.0.
    Source (.tar.gz) For unix systems; uses linefeeds as line delimiters.
    Source (.zip) For Windows and OS/2 systems; uses CR/LF pairs as line delimiters.

    Code for running MIT Scheme under GNU Emacs is here (or byte-compiled); this has been tested on GNU Emacs versions 19.34 and 20.5a, and should replace the file of the same name included with Emacs. 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 Scheme compiler to do the compilation. 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.

    There is one exception to this statement: if you are running a unix-like operating system on the Intel 32-bit architecture, the code in the "microcode" subdirectory of the source tree is C code, and contains nearly all of the operating-system specifics. You can compile the C code to produce executables and combine that with one of the existing packages to make a new package. See these instructions for an outline of the procedure.

    Future Plans

    We don't have firm plans for a next major release at this point. Sometime in 2001 or 2002, we plan to port MIT Scheme to the Intel Architecture 64 (Merced) running GNU/Linux. Depending on time constraints, we will also update MIT Scheme by implementing R5RS-compliant hygenic macros, and changing #f and the empty list to be distinct objects.

    This page is maintained by Chris Hanson.
    Last changed on Wed Dec 31 19:00:00 1969.