   AUC TeX is a comprehensive customizable integrated environment for
writing input files for LaTeX using GNU Emacs.

   AUC TeX lets you run TeX/LaTeX and other LaTeX-related tools, such
as a output filters or post processor from inside Emacs.  Especially
`running LaTeX' is interesting, as AUC TeX lets you browse through the
errors TeX reported, while it moves the cursor directly to the reported
error, and displays some documentation for that particular error.  This
will even work when the document is spread over several files.

   AUC TeX automatically indents your `LaTeX-source', not only as you
write it -- you can also let it indent and format an entire document.
It has a special outline feature, which can greatly help you `getting an
overview' of a document.

   AUC TeX is written entirely in Emacs-Lisp, and hence you can easily
add new features for your own needs.

Homepage:
https://www.gnu.org/software/auctex/
