FONTpage is a utility for viewing, managing, and generating images of fonts. It can install and delete per-user fonts as well as (when run as root) system-wide fonts. It displays fonts, has a full alpha-numeric popup window, and allows you to change the font size and color, background color, font face, bold, and italics. It also has the ability to input the text to be displayed, which you can choose to save as a PNG file. It is handy to view fonts and styles quickly, or to make "logo" graphics. And naturally, it is a simple way to try out fonts without dipping into the command line. The source code as well as Slackware packages are available.
Fontlinge searches for font files, sorts them into folders by name and look and with human readable names, stores gathered font information in a database, generates previews and posters, finds and removes duplicates, and reunites PostScript font families. Also, Fontlinge has a Web interface to browse through your fonts. It shows detail previews and font info, provides font download as a tarball, and has the possibility to sort fonts.
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.