Astwar is a ncurses based simple space shooter; two little ships (asterisks), each on one side of the screen, try to shoot each other. There is network support with several multiplayer options and user extension with Scheme (via Guile) to program the little ship to do some things automatically are in the works.
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.
Dolda Connect is a modular P2P filesharing client built around the Direct Connect model. It supports most of the latest features of the DC protocol. It runs in client/server mode with a well defined protocol, allowing extensibility, flexibility, and multiple detachable user interfaces. It also has an optional multi-user mode.
Eleven is a programming language for creating robust, scalable Web applications quickly and easily. It offers a 20x programmer productivity increase over traditional server programming languages like ASP, PHP, and JSP by automating state management and taking control of the application's look and feel. From high-level source code with a simple, C-like syntax, the compiler generates complete, ready-to-run implementations in PHP or mod_perl. Applications maintain their state in a relational database and are inherently fault-tolerant, secure, and scalable.
FramerD is a semi-structured object database integrated with a Scheme-based scripting language which supports multi-lingual programming (with pervasive Unicode), a stable module system for programming in the large, distributed applications (via an extensible RPC protocol), non-deterministic (PROLOG-like) evaluation for search and set operations, multi-threaded program execution, extensive tools for text and language analysis, built-in HTML/XML/MIME parsers, and intuitive (CGI- and FastCGI-based) Web scripting. The built-in object database robustly supports millions of objects and indexed access to those objects, both through disk files and networked servers.
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.