CLSQL is an SQL database interface for Common Lisp. It provides object-oriented and functional access methods to the underlying database, which can be one of MySQL, ODBC, PostgreSQL, or SQLite. It uses the Unified Foreign Function Interface (UFFI) and thus supports the CMU Common Lisp, Steel Bank Common Lisp, and Allegro Common Lisp implementations.
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.
DSWM (Deep Space Window Manager) is a tiling keyboard-driven X11 window manager. It is based on StumpWM code and is written entirely in Common Lisp and oriented for good usability with minimum startup configuration and good integration with Emacs. The project is under hard development, so it has many experimental features.
Lisp Blosxom is a port of the Perl Blosxom blogging engine to ANSI Common Lisp. Its goals are extensibility and speed. It's a filesystem-based blogging engine, which means that blog entries are just flat files on disk, although plugins can be written to extend or replace this behavior. The first line in the file is the title, while the remainder is the text of the body. Entry dates are taken directly from the filesystem's modification date for each entry. Furthermore, the structure of the blog is taken directly from the hierarchy of directories and files on disk.
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.