Chez Scheme
Petite Chez Scheme

(chez (chez scheme))

Welcome to the home of Chez Scheme, where you'll find information on and resources relating to Chez Scheme, a powerful implementation of Scheme designed to maximize programmer productivity as well as application reliability and performance.

Chez Scheme Version 9.4 (Open Source)

See github.com/cisco/chezscheme.

Chez Scheme Version 8.4

Chez Scheme Version 8.4 is now available. One highlight of this release is support for manipulating annotations, which the expander and compiler use to track source information. Another is compile-time creation of constant, immutable record instances. Please see the release notes for a description of these and other changes. For pricing and ordering information and other inquiries, please contact us.

As always, Petite Chez Scheme is available for use without fee. Petite Chez Scheme is built from the same sources as Chez Scheme, but without the compiler. It serves both as a royalty-free run-time environment for compiled Chez Scheme programs and as a complete interpreter-based Scheme implementation for those who do not require the extra functionality and performance delivered by the compiler. Download it now and try it out.


Documentation for Chez Scheme comes in two parts. The The Scheme Programming Language, 4th Edition (TSPL), which is a general introduction to and reference for Scheme. It is available for order direct from MIT Press and various online and local retailers. The full text is available online, along with errata.

The Chez Scheme Version 8 User's Guide (CSUG), which is specific to Chez Scheme, can be purchased from lulu.com. The full text is also available online, along with errata.

Chez Scheme Version 7.4d

Chez Scheme Version 7.4d, an implementation of R5RS Scheme with numerous extensions, while no longer supported, is still available, including the free Petite Chez Version 7.4d.