TXR is a new data munging language. TXR's special pattern language provides template-based matching of entire documents or large sections of documents. It also contains a language for functional and imperative programming. It is written in C and takes the form of a utility that is portable to Unix-like platforms and Windows.
MDK (MIX Development Kit) provides tools for developing and executing, in a MIX virtual machine, MIXAL programs. The MIX is Donald Knuth's mythical computer, described in the first volume of The Art of Computer Programming, which is programmed using MIXAL, the MIX assembly language. MDK includes a MIXAL assembler (mixasm), a MIX virtual machine (mixvm) with a command line interface, a Guile-based virtual machine (mixguile), a GTK+ based GUI (gmixvm), and a mixvm-Emacs interface (mixvm.el). MDK utilities are extensible using Scheme.
Librep is a shared library implementing a Lisp dialect that is lightweight, reasonably fast, and highly extensible. It contains an interpreter, byte-code compiler, and virtual machine. Applications may use the interpreter as an extension language, or it may be used for standalone scripts. Rep was originally inspired by Emacs Lisp. However one of the main deficiencies of elisp--the reliance on dynamic scope--has been removed. Also, rep only has a single namespace for symbols.
sawfish.wm.ext.pager is a C/Lisp extension that provides a functional desktop pager for the sawfish window manager. A pager is a map of your desktop. It shows not only the visible part of your desktop (the current viewport), but also the parts that extend beyond the sides of your screen. Also, if you have more than one workspace, the pager will follow you to where you are, or optionally show all workspaces at once. Of course you can select viewports and windows, and also move or raise/lower the latter.
Nerd is an attempt to create a cross-platform scripting language that is based on Scheme and easy to embed, extend, and use. It's currently used in video game projects and is interpreted only. There are definite future plans to add a byte-code compiler and VM to it and to write proper documentation.
Lush is a Lisp dialect with extensions for object-oriented and array-oriented programming. It is intended as a programming environment for prototyping numerically intensive applications. Unlike alternatives like Python or SciLab, Lush is designed for easy integration of existing C/C++/Fortran codes.