Common Lisp Quick Reference is a booklet with short descriptions of the thousand or so symbols defined in the ANSI standard. It comes with a comprehensive index. It is written in LaTeX and formatted for printing on both A4 and letter paper. After folding the sheets lengthwise, they can easily be turned into a handy booklet.
TextSearch is a program to search through a set of text files in a directory structure. Each document is searched using a regular expression and an overview of the results is shown as a tree structure. By clicking on a file, it can be viewed, with matches being highlighted. As opposed to other programs out there, its focus is not so much on statistics, i.e. how often a word would occur in an entire corpus of files, but rather on occurrences in single files.
GNU Lightning is a library that generates assembly language code at run time. It is very fast, making it ideal for Just-In-Time compilers, and it abstracts over the target CPU, as it exposes to the clients a standardized RISC instruction set (inspired by the MIPS and SPARC chips).
The Header and Envelope rewrite mini-HOWTO explains how to rewrite your from address differently in the mail header and the mail envelope. This may be necessary, for example, if your ISP requires you to send mail with one address, but you are subscribed to mailing lists with a different address, or want others to see a forwarding address instead of your ISP's address.
Webtester is an application which is intended to be used in the testing and validation of Web-based applications. By reading an XML configuration file, the application is able to call URLs and use regular expressions to examine the results. Features include support for SSL, cookies, and variable assignment/substitution when sending and examining data.