GNU TeXmacs is a free wysiwyw (what you see is what you want) editing platform with special features for scientists. The software aims to provide a unified and user friendly framework for editing structured documents with different types of content: text, mathematics, graphics, interactive content. TeXmacs can also be used as an interface to many external systems for computer algebra, numerical analysis, and statistics. New presentation styles can be written by the user and new features can be added to the editor using Scheme.
make_faq is an HTML generator that builds chunks/chapters/questions-and-answers or whatever, and builds indexes to hold it all together. It's a fairly general purpose tool for creating a set of indexed pages, but it's common usage is to build FAQ (Frequently Asked Questions) HTML from text documents. See the examples for a better understanding.
PhpWiki is a WikiWikiWeb clone written in PHP. A Wiki is a Web site where anyone can edit or create the pages through the Web browser, with no authentication. PhpWiki works right out of the box with zero configuration, and comes with a set of default pages. It's useful for collaborating on documentation on a project, having freeform discussions, and easy editing and searching.
PyleWiki is a WikiClone written entirely in Python that allows a group of people to collaboratively edit a tree of webpages using nothing but their browser and a simple, text-based markup language. This particular WikiClone has a few extensions to the original: attachments to pages, user authentication (primitive), and the use of templates for page styling among others.
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.
Site Index is a simple script which generates HTML pages showing a site index for all of your local domains. It uses the natural hierarchy of your filesystem, so if you've organized your pages well, the job is fully automated. It breaks the index into multiple pages to respect a links-per-page limit, and can do some sorting/management of the results according to domain/page "importance".
TrinityOS is a step-by-step, example-driven HOWTO on building a very functional Linux box with strong security in mind. TrinityOS is well known for its strong packet firewall ruleset, Chrooted and Split DNS (v9 and v8), secured Sendmail (8.x), Linux PPTP, Serial consoles and Reverse TELNET, DHCPd, SSHd, UPSes, system performance tuning, the automated TrinityOS-Security implementation scripts, and much more.
Txt2tags converts a text file with minimal markup to HTML, XHTML, SGML, DocBook, LaTeX, Lout, Man page, Creole, Wikipedia, Google Code Wiki, PmWiki, DokuWiki, MoinMoin, MagicPoint, PageMaker, AsciiDoc, or ASCII Art. It is simple and fast and features automatic TOC, macros, filters, include, tools, GUI, CLI, and Web interfaces, translations, and extensive documentation.