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Minimal Scheme Implementation for use as an Extension Language

Chibi-Scheme is a very small library intended for use as an extension and scripting language in C programs. In addition to support for lightweight VM-based threads, each VM itself runs in an isolated heap allowing multiple VMs to run simultaneously in different OS threads.

There are no external dependencies so is relatively easy to drop into any project.

Despite the small size, Chibi-Scheme attempts to do The Right Thing. The default settings include:

  • a full numeric tower, with rational and complex numbers
  • full and seamless Unicode support
  • low-level and high-level hygienic macros
  • an extensible module system

Specifically, the default repl language contains all bindings from R7RS small, available explicitly as the (scheme small) library. The language is built in layers, however - see the manual for instructions on compiling with fewer features or requesting a smaller language on startup.

Chibi-Scheme is known to work on 32 and 64-bit Linux, FreeBSD, NetBSD, OpenBSD and OS X, Plan 9, Windows, iOS, Android, ARM and Emscripten. Basic support for native Windows desktop also exists. See for details and build instructions.

To build on most platforms just run make && make test. This has a few conditionals assuming GNU make. If using another make, there are a few parameters in Makefile.detect you need to set by hand.

This will provide a shared library libchibi-scheme, as well as a sample chibi-scheme command-line repl. You can then run

sudo make install

to install the binaries and libraries. You can optionally specify a PREFIX for the installation directory:

make PREFIX=/path/to/install/
sudo make PREFIX=/path/to/install/ install

By default files are installed in /usr/local.

If you want to try out chibi-scheme without installing, be sure to set LD_LIBRARY_PATH so it can find the shared libraries.

To make the emscripten build run make js (not emmake make js).

For more detailed documentation, run make doc and see the generated doc/chibi.html.