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.
TeXtrace is a collection of scripts that convert any TeX font into a Type1 .pfb outline font immediately suitable for use with dvips, pdftex, Acroread, and many other programs. The main advantage of using Type1 fonts with TeX is that Acroread renders TeX's bitmap fonts ugly on screen, but it renders outline fonts beutifully and fast.
Copper is a Web-based project management software tool designed to help creative teams manage clients, projects, tasks, files, budgets, and events. It has an HTML/AJAX front end. It is available with full source for a licence fee or as a SAAS hosted service (compatible with iPhone, but available via PC/Mac/Linux and a Web browser).
OmegaT is a translation memory application intended for professional translators. It does not translate for you (software that does this is called "machine translation"). It features fuzzy matching, match propagation, simultaneous processing of multiple-file projects, simultaneous use of multiple translation memories, and external glossaries. Document file formats include plain text, HTML, and OpenOffice.org/StarOffice. It has Unicode (UTF-8) support (can be used with non-Latin alphabets). It is compatible with other translation memory applications (TMX Level 1).