GNU TeXmacs is a free scientific text editor, which was both inspired
by TeX and GNU Emacs. The editor allows you to write structured
documents via a wysiwyg (what-you-see-is-what-you-get) and user-
friendly interface. New styles may be created by the user. The
program implements high-quality typesetting algorithms and TeX
fonts, which help you to produce professional-looking documents.

WWW: http://www.texmacs.org/