Scsh is a systems-programming environment for POSIX systems and Win32, embedded in the Scheme programming language. It includes a high-level process notation for writing shell-script like programs, with pipelines and redirections. Scsh additionally provides low-level access to POSIX primitives, plus important non-POSIX extensions such as sockets. Scsh is implemented on top of Scheme48, a portable bytecode implementation of Scheme. A number of user-contributed extensions are available, including an extensible HTTP and FTP server, a socket-level PostgreSQL interface, a programmable text formatting language, and a Postscript generation language.
GNU Anubis is an SMTP message submission daemon. It represents an intermediate layer between the mail user agent (MUA) and mail transport agent (MTA), receiving messages from the MUA, applying to them a set of predefined changes, and finally inserting modified messages into an MTA routing network. The set of changes applied to a message is configurable on a system-wide and per-user basis. The built-in configuration language used for defining sets of changes allows for considerable flexibility and is easily extensible.
Gauche is an R5RS Scheme implementation that aims to be a handy tool for daily work. Quick startup, a built-in system interface, and native multilingual support are some of its goals. It has an OO system similar to STklos and Guile. It supports UTF-8, EUC-JP, and Shift-JIS multibyte encodings natively.
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.
SCRIBE is a text processor. Even if it is a general purpose tool, it best suits the writing of technical documents such as web pages or technical reports, API documentations, etc. At first glance, it looks like a mark-up language a la HTML, so there is no need for computer programming skills to use it. A second look reveals that it is actually a true programming language, based on Scheme, provided with high-level features (such as objects, higher order functions, regular and syntactic parsing, etc.).
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.