Sfront compiles MPEG 4 Structured Audio (MP4-SA) programs into efficient C programs that generate audio when executed. MP4-SA is a standard for normative algorithmic sound, which combines an audio signal processing language (SAOL) with score languages (MIDI and SASL). Under Mac OS X and Linux, sfront supports real-time, low-latency audio input/output and MIDI input. Under Mac OS X, sfront supports the creation of AudioUnit plug-ins. The documentation includes a book about SAOL programming.
SGMLtools-Lite is the successor of SGMLtools. It is a set of Python and DSSSL scripts which makes interaction with Jade in order to process (mostly DocBook) SGML files a breeze, and is easy to extend with custom processing instructions. Out of the box, SGMLtools-Lite knows how to convert DocBook to HTML (2 styles), JadeTeX, DVI, RTF, PS, PDF, plain text, and PalmOS iSilo format. It also comes with a conversion script to convert "old" LinuxDoc documents to DocBook.
sgtd (Simply Getting Things Done) is a curses-based application based on the GTD concepts in the book "Getting Things Done", by David Allen. It features a simple clutter-free UI and vi-like bindings in order to keep your fingers in touch-typing position at all times. It allows you to enter the next action items to get them out of your head, to organize the next action items into projects, and to assign contexts in which next actions can be performed.