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 professionally
looking documents.
The high typesetting quality still goes through for automatically generated
formulas, which makes TeXmacs suitable as an interface for computer algebra
systems. TeXmacs also supports the Guile/Scheme extension language, so that
you may customize the interface and write your own extensions to the editor.