GNU TeXmacs is a free scientific word processor and typesetting component of the GNU Project. It was inspired by TeX and GNU Emacs, though it shares no code with those programs. TeXmacs does use TeX fonts. It is written and maintained by Joris van der Hoeven. The program produces structured documents with a WYSIWYW user interface. New document styles can be created by the user. The editor provides high-quality typesetting algorithms and TeX fonts for publishing professional looking documents.
Read more about GNU TeXmacs: Features, Supported Back Ends