A portable debugger for the Scheme language. It presents the user with an interactive interface that lets him or her examine and change values of variables, set breakpoints, and single step evaluation. Psd is designed to be run within GNU Emacs, which is used for displaying the current source code position.

A portable Scheme library providing compatibility and utility functions for standard Scheme implementations. By Audrey Jaffer, author of SCM.

A module proposal for Scheme by Audrey Jaffer.

A digital logic simulator written for the SCM Scheme implementation.

HITCH (HIghlighT CHanges) highlights changes between two sets of HTML pages in red. INFOBAR annotates changes between GNU Info files with change-bars.

An interactive symbolic mathematics program. It can manipulate and simplify equations, scalars, vectors, and matrices of single and multiple valued algebraic expressions containing numbers, variables, radicals, and algebraic differential, and holonomic functions.

A partial evaluator for a pure (side effect free) subset of Scheme, written primarily by Charles Consel. Some of its main features are polyvariant binding-time analysis, treatment of higher-order functions and partially static data structures, colored binding-time information based on GNU emacs (19.30 or later), and a binding-time inspector. The current version is 010 and requires an R4RS Scheme and the SLIB library.

A partial evaluation system for Scheme: Given a program P and a specification of which of the inputs are known in advance, PGG outputs a program generator which accepts the known inputs of P and outputs a specialized version of P. PGG is fully automatic and can process all valid Scheme programs.

A generator for LR(k) and SLR(k) parsers in Scheme. The generated parsers perform error recovery, and are highly efficient. They result from the general parser by an automatic program transformation called partial evaluation. This guarantees consistency and ensures correctness. However, no specific knowledge of partial evaluation is required to use Essence. From Michael Sperber [Mr. Preprocessor] and Peter Thiemann.

An extension of the Scheme programming language to support research in computer vision.

A collection of libraries for common internet protocols for SCSH, the Scheme Shell.

A language designed for server-side WWW-based applications, particularly database applications. It is based on Scheme (using Kawa Scheme), which makes the syntax extremely simple yet powerful.

A small, lightweight MUD based around dueling wizard wars. Features the use of Scheme as a worldbuilding language.

A highly configurable X window manager written and configurable with Guile Scheme. An absolute must for any hardcore Schemer who uses X Window. Now at version 0.99.6.1 with Gnome support, a CORBA interface, a complex constraint system for pseudointelligent window placement and management, extremely flexible decoration configurability, and a GUI configuration interface for non-Scheme hackers, plus an assortment of decoration themes.

A version of AWK in the Scheme programming language. It goal is to offer the same features as awk to scheme programmers.

An XML Framework for Scheme combines an abstract datatype for XML ("RS-XML") with a system for creating Scheme-ish macros for transforming XML. Also included is a embedding of CSS.

An embedding of Prolog-style logic programming in Scheme. Prolog-style and conventional Scheme code fragments can be used alongside each other.

An autoprojector (self-applicable partial evaluator) for a large higher-order subset of the strict functional language Scheme, written by the Similix Group of DIKU. Similix treats source programs that use a limited class of side-effects, for instance input/output operations. The current version is 5.1. Similix 5.1 is also bundled with the Simu system written by Liping Zong; an X Window interface to Similix.

A CLOS-like Object System for Scheme.

A permissive HTML parser for Scheme that emits SXML format so that real-world HTML can be processed with XML query and transformation tools.

A functional Scheme based XML parsing framework consists of a (semi-validating) DOM/SXML parser, a SAX parser, and a supporting library of lexing and parsing procedures.

A whole handfull of Scheme programs and applications, including Treaps ("A sorted dictionary data structure based on randomized search trees."), Scheme database interfaces, parsing utilities for CGI and XML, binary I/O and applications, POSIX interfaces, a purely functional OO system, and read-time application.

For DrScheme, semi-structured program editing; an alternative set of key bindings. When it is on, the most important functions can run via unchorded keystrokes, and motion commands work on sexps by default.

A CLOS-like object system for MzScheme. Many other extensions like a generalized set. (a la SRFI-17).