latex-preview-pane is a minor mode for Emacs that enables you to preview your LaTeX files directly in Emacs.
It supports PDF previews, your choice of pdflatex or xelatex, and it highlights errors in your LaTeX buffer.

To enable, place the following in your .emacs file:

(latex-preview-pane-enable)

As an alternative, you may enable it on the fly with:

M-x latex-preview-pane-mode

The latest version of latex-preview-pane can always be found at
https://github.com/jsinglet/latex-preview-pane

You can find the documentation for latex-preview-pane either on GitHub (above) or
on EmacsWiki at: http://www.emacswiki.org/emacs/LaTeXPreviewPane