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SP-Forth is a reliable and comfortable forth system producing optimized native code for the Intel x86 processors. It runs on MS Windows 9x, NT and Linux.

SP-Forth is free software, see LICENSE section for more information.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


SP-Forth (SPF) for Windows is distributed as an archive or the self-installing executable.

If you have an executable package - just run it. The wizard will guide you through the setup process.

If you've got an archive - unpack it to the desired folder. It is ready to use now. If you want to associate *.f and *.spf files with spf4.exe - run docs/install/install.bat script, which will launch a GUI program for tweaking the registry settings. Alternatively you can edit docs/install/spf_path_install.reg manually (specify the correct path to your spf4.exe) and run it. Now you can write your code, save it as the *.f file and execute it by simply doubleclicking the source file.


SP-Forth for Linux is distributed as a source tarball or packaged for specific Linux distribution (currently Debian only).

After unpacking tarball put the symlink to spf4 binary somewhere in your path. So it will find required lib and devel files. You will need gcc to compile src/posix/consts.c to generate platform-specific code.

The packaged version will install the root tree in separate directories, according to the distro recommendation (/usr/bin, /usr/lib and /usr/share). Source code is patched to correctly find lib and devel directories. At startup spf will include ~/.spf4.ini.


See the docs/whatsnew.en.txt file for the short overview of recent changes.


  • /devel - additional contributed libraries and examples
  • /docs - documentation
  • /lib - standard libraries, ANS and non-ANS extensions like float.f, locals.f ...
  • /samples - debugged GUI and console mode samples.
  • /src - full sources with comments and compilation script.

Files in the root directory:

  • help.fhlp - default include for the lib/ext/help.f extension
  • jpf375c.exe - an older version of SPF used to build itself
  • spf4.exe - SPF itself
  • spf4.ini - This file is automatically included by SPF at startup


See the /docs directory. The majority of the documentation is in Russian for now. If you need an English version, contact us, the translation will be done.

  1. SPF specifics

    If you are familiar with Forth, but not with SPF.

  2. Short overview of libraries

    Additional libraries in SPF distribution

SPF extension (lib/ext/help.f) adds help support to the interpreter with the word HELP.

If you have more questions - ask them at spf-dev mailing list.



You can modify and/or redistribute the core SP-Forth system (i.e. all files in src) under the terms of GNU GPL as published by FSF. All other files, including contrubuted code in devel, are licensed under GNU LGPL by default (if not stated otherwise).

Shortly speaking it means that :

  • You are prohibited to modify core SPF system and distribute the result of this modification without providing full sources.

  • You are allowed to compile and distribute closed-source projects with original SPF.

  • You are allowed to use unmodified code from devel in combination with your own code in closed-source projects.

  • You are obliged to contribute back your modifications to original code from devel if you modified and used it in closed-source project, but you may leave your own code closed.


Russian Forth Interest Group with the help of many contributors.

Started by Andrey Cherezov in 1992

Last updated : $Date: 2009/01/21 17:02:13 $