WP LaTeX creates PNG images from inline $\LaTeX$ code in your posts and comments.
This plugin can generate the PNG images either by using WordPress.com's LaTeX server (recommended) or by using the version of LaTeX installed on your webserver (LaTeX is not installed on most webservers; this method is recommended for advanced users only).
If you choose this advanced method, you will need several external programs to be installed and working on your webserver, so installation is bit complicated. Many hosts will not be able to support this method.
texlive-latex-basepackage together with the
tetex-math-extrapackage. Both are available to most Linux distributions.
dvipng(provided by the
dvipngpackage) or both
convert(provided by the
graphicsmagickpackages, respectively) must installed as well.
wp-content/directory and make it writable by your webserver (chmod 777 will do the trick, but talk to your host to see what they recommend).