ACL2 is a mathematical logic, programming language, and mechanical theorem prover based on the applicative subset of Common Lisp. It is an "industrial-strength" version of the NQTHM or Boyer/Moore theorem prover, and has been used for the formal verification of commercial microprocessors, the Java Virtual Machine, interesting algorithms, and so forth.
CL-BibTeX is a replacement for the BibTeX program, written in Common Lisp. The aim is to enable the user to format bibliographic entries using Common Lisp programs, rather than using the stack language of BibTeX style files. A compiler that transforms BibTeX style files into comprehensible Common Lisp programs is included.
Charlemagne is a versatile genetic programming application. It includes a commandline client and an interactive console mode. It is written in Python and Lisp, and is user extensible to some degree in both languages. It features built-in input-output mapping support and provides the ability to define complex fitness calculations in Lisp or Python.
Etiquette is an interaction protocol construction toolkit. The project's goal is to build a framework for rapid design of network communication code. Etiquette interaction protocols are intended to describe valid communication processes that can occur in networked applications, along with error-handling code. Etiquette provides protocol tracing and single-stepping support.
Fract is a Web-based fractal zoomer for the Mandelbrot set. It has no advanced features, for the goal is to keep the code easy to read for someone interested in fractals. The package also includes an offline renderer that you can use to generate high resolution images of your favorite spots. You can also easily play with the color map.
HO-CVS is a version control system based on MetaCVS. In addition to the features of MetaCVS, it features module level versioning, the ability to reference every version (since there is a tag after every commit, which is extremely useful but slow), complex versions like #v1.2.3 designed to carry information about the change, operation hooks, and a somewhat powerful log command.