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.
SILGraphite (formerly OpenGraphite) is a project within SIL's Non-Roman Script Initiative and Language Software Development groups to provide extensible cross-platform rendering capabilities for complex non-Roman writing systems. It consists of a rule-based programming language, Graphite Description Language (GDL), that can be used to describe the behavior of a writing system, a compiler for that language, and a rendering engine that can serve as the backend of a text processing application. SILGraphite renders TrueType fonts that have been extended by means of compiling a GDL program. It is currently being integrated into Gecko/Mozilla through the SILA project, a GNU/Linux port is also underway, and there are plans for OpenOffice.org and Abiword integration.
PalmFontConv is a collection of command-line utilities to manipulate Palm fonts in both v1 and v2 formats. Currently, there is a converter that converts between afnx, nfnt (low, high, or both densities), NFNT, and text editable formats, and another converter that converts Type 1/TrueType/BDF/PCF and other formats supported by FreeType2 into the text editable format, code for generating Plucker and PalmBible+ compatible anti-aliased fonts. There are also a bunch of GUI shells for generating font packages for Plucker, PalmBible+, Fonts4OS5, and FontSubst.
rxvt-unicode is a clone of the well known terminal emulator rxvt, modified to store text in Unicode and to use locale-correct input and output. It also supports mixing multiple fonts at the same time, including Xft fonts, real transparency, and an optional embedded Perl interpreter that allows you to extend your terminal easily.
libtholoura is a text-image distortion library, which is useful for sites that want to ensure that a human (and not a bot) is viewing pages. It is optimized to produce images of strings distorted in a way that makes it impossible for an OCR to read, but humans can. The library takes a string (preferably ASCII) string and is able to dynamically produce PNG indexed images. The distortion filters are external plugins.
Univert is a Universal Unicode Converter, at least as universal as the Unicode implementation in Tcl 8.1 or later can manage on your computer. Univert will convert interchangably between the following formats: native Tcl unicode, hex bytes or words separated by spaces, decimal bytes or words separated by spaces, HTML entities, UTF-8/URL encoding, quoted printable with whatever the current encoding is, and C string with whatever the current encoding is.