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.
Avsomat is a variable star astronomy framework. It supports the automating of observation scheduling, identification and photometry of variable stars on CCD images, reporting, management, and verification of results. It uses electronic charts of the variable star fields and maintains a view of the current results in the form of a collection of interlinked Web pages with feedback forms, allowing members of the observer community to participate in locating errors.
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.
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.
Allegro Common Lisp is a full ANSI Common Lisp (1994) implementation. It contains many extensions, including 32- and 64-bit native compilation, efficient built-in memory management, foreign functions (for interfacing with other languages), multiprocessing, UNICODE and locale support, XML/HTML parsers, a Web client and server, GTK+ interface (1.2 and 2.0), Java interface, OLE interface (Windows only), profiler, regular expressions, an XML RPC implementation, native Lisp RPC, sockets, DLL and shared library support, and more.