The Advanced Bash Scripting Guide is both a reference and a tutorial on shell scripting. This comprehensive book, the equivalent of 1,000+ print pages, covers almost every aspect of shell scripting. It contains 382 profusely commented illustrative examples, a number of tables, and a cross-linked index/glossary. Not just a shell scripting tutorial, this book also provides an introduction to basic programming techniques, such as sorting and recursion. Included scripts are the Game of Life, a Perquackey variant, a Morse code trainer, and an implementation of the Gronsfeld Cipher. This book is suited for both individual study and classroom use. It covers Bash, up to and including version 4.2. Note that users of miniaturized single-board computers running Linux, such as the Raspberry Pi and the Beagle Bone, would find this Guide useful for learning and running Bash scripts to explore and expand the capabilities of these small, but powerful machines.
tkbiff allows arbitrary commands to be executed upon mail reception. If you like programs such as xbiff and xbiff++ but wish they were more flexible, then you'll like tkbiff. Unlike other biffs, tkbiff is fully customizable. tkbiff also doesn't waste your valuable screen space with icons; instead, it shows you the mail itself. It supports UNIX, Mac, and Windows, IMAP, POP, and UNIX-style mail files, and SSL and APOP.
The Spoofaudit network auditing tool will help you to determine what basic spoofing filters (rfc2827 & rfc3013) are present between two test points on two networks, and what anti-spoofing filters are missing. The tools are designed to work between endpoints that would not normally have filtering between them except anti-spoofing filters.
Ersatz Emacs is a very minimal imitation of the famous GNU Emacs editor. Unlike most popular Emacs derivatives, Ersatz strives to use as little system resources as possible and be simple enough for the casual programmer to understand, yet still include all the functionality required for most text editing jobs. Thirteen years ago this was the Public Domain release of MicroEmacs 3.6 as posted to mod.sources.
UltiMusE-LX is a composing program. You could think of it as a "word processor" for music. It allows you to draw sheet music on the screen using the mouse and/or computer keyboard. Up to 16 parts or voices fit on up to seven staves. Most standard musical notations are supported, as are MIDI instrument patch changes, events, and real-time clocks. As you work, you can hear your music played from any point in your score, or print any portion of it. Your completed score file documents your composition and arrangement in as much detail as you care to put in. UltiMusE was for many years the standard MIDI program for the Tandy Color Computer OS-9 community.