The Remembrance Agent (RA) watches your over your shoulder and continuously updates a list of documents relevant to what is being typed or read in an Emacs buffer. Suggestions are then displayed in their own window at the bottom of the frame, and are continually updated every few seconds. The RA uses a multi-field information-retrieval back-end called Savant that can index several different kinds of files, including email archives, HTML, LaTeX, and plain text format.
rpl is a Unix text replacement utility. It will replace strings with new strings in multiple text files. It can scan directories recursively and replace strings in all files found. The search can be limited to files with certain filename suffixes (e.g. '.html', '.c', etc.). It includes source, a build script, and a man page. It should work on most flavors of Unix. Linux/Intel, Linux/PPC, and source RPMs are available, as are binaries for other OSes, including Mac OS X.
Rute (Rute Users Tutorial and Exposition) is a book on GNU/Linux that aims to be the definitive guide for new users as well as sufficing as training course material, covering both the RHCE and LPI requirements. It covers essential theory to UNIX as well as giving practical tutorials on all fundamental aspects of Unix administration, from basic commands, the theory of TCP/IP, the Linux filesystem, through to configuration of mail, DNS, and other servers, through hardware configuration and package management. It is not Unix-specific but tends to give examples suited to Debian and RedHat-like systems. Rute comes in HTML and PDF formats.
Setedit is a text editor specially designed for programmers. It has a nice interface with mouse support, menus and windows (text mode). The editor is a very good choice for people with DOS background, especially people accustomed to Worstar and Borland editors. The editor has overlapped windows so you can see more than one file at the same time, configurable syntax highlighting, macros, rectangular selection, block indentation, as well as customizable keyboard shortcuts and menus.
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.
Siag Office is a free office package which consists of the spreadsheet Siag, the word processor PW, the animation program Egon, the text editor XedPlus, the file manager Xfiler and the previewer Gvu. Siag is easy to use, yet infinitely flexible through multiple embedded interpreters and a plugin mechanism that allows other programs to run inside the main document. The supported interpreters are SIOD, Guile, Tcl, and Python.