LyX - A WYSIWYM document processor.
LyX is a document processor that encourages an approach to
writing based on the structure of your documents (WYSIWYM)
and not simply their appearance (WYSIWYG).
LyX combines the power and flexibility of TeX/LaTeX with the
ease of use of a graphical interface.
This results in world-class support for creation of mathematical
content (via a fully integrated equation editor) and structured
documents like academic articles, theses, and books.
LyX requires a working installation of TeX/LaTeX. For this you
may install Texlive packages available here or from Texlive DVD.
WARNING: Note that tetex, the TeX package in the base Slackware
distribution was abandoned more than 10 years ago and needs to be
replaced with the latest version of Texlive for best experience
with LyX.