GNU TeXmacs is a free wysiwyw (what you see is what you want) editing platform with special features for scientists. The software aims to provide a unified and user friendly framework for editing structured documents with different types of content: text, mathematics, graphics, interactive content. TeXmacs can also be used as an interface to many external systems for computer algebra, numerical analysis, and statistics. New presentation styles can be written by the user and new features can be added to the editor using Scheme.
Chicken is a Scheme compiler that translates most of R5RS Scheme into relatively portable C. It supports fully general tail-call recursion, first-class continuations, and has a very flexible and efficient interface to C and C++. Chicken implements several extensions to the Scheme language: lightweight threads, pattern matching macros, dynamic loading of compiled code, and various object-oriented paradigms, such as TinyCLOS, and others. The library system includes hundreds of convenient modules for practical use.
TinyScheme is a lightweight Scheme interpreter that implements as large a subset of R5RS as possible without getting very large and complicated. It is meant to be used as an embedded scripting interpreter for other programs. As such, it does not offer IDEs or extensive toolkits although it does sport a small top-level loop, included conditionally. A lot of functionality in TinyScheme is included conditionally, and it allows multiple interpreter states to coexist in the same program without any interference between them. Foreign functions in C can also be added and values can be defined in the Scheme environment.
ILISP is a package that is designed to integrate various Lisp implementations (mostly Common Lisp systems and various Scheme dialects, including Guile) within Emacs (or XEmacs). ILISP runs an inferior Lisp process (in Emacs parlance) and provides a specialized set of commands, key bindings, and menus to ease the interaction with it. ILISP commands access the underlying Lisp process and provide ways to make the editing, compilation, and execution of Lisp programs much easier.
CodeApplet is a Java-based client-server system that is meant to be used for teaching computer programming online. It may be used with any language for which an appropriate Java class is written, and adding a new interpreter requires no recompilation of the main binaries. Users connect to different coding sessions on the server. Every session has one editor at a time, elected by privileged operators or the current editor. This editor may control a shared language interpreter and edit source files while the other users watch in realtime. Some languages also support local interpreters for personal experiments.