Since I have updated Joomla to 1.5x, moslatex does not work here.  The TeX codes in this post will not show. The instructions are still valid.  For Joomla 1.5x, some good plug-in and module for LaTeX are available.  See this blog for some information.  

Now I am on Joomla 1.6 3.4 and using MathJax to render $\LaTeX$ formula.  The following IS NOT USED ANYMORE. One nice thing is that I can simply copy $\TeX$ code and paste into my article. See this article.


 

Now $\LaTeX$ is supported via moslatex bot (not supporting Joomla 1.5 yet), you can have in-line formula like $a+b+c^d$ or displayed formula like $$E\star F=\big\{ a^{(k_i-k_0)(k_i'-k_0')}b^i\mid 0\leq i\leq t-1\big\}$$ Multiline coded formula is supported as well.

For example, the above displayed formula is done with the commands:

\[E\star F=\big\{ a^{(k_i-k_0)(k_i'-k_0')}b^i\mid 0\leq i\leq t-1\big\}\]

Installation Notes.  Since I am uising MikTeX + imagemagick + ghostscript, some parameters needs to be changed as well (also make sure that the path to the bin and lib directories of ghostscript  are included in your system's PATH):

(/mambots/content/moslatex.php):

  •  $botMosLatex_builder = new LaTeX_Builder(
    $mosConfig_live_site . '/mambots/content/latex/cache',
    $mambotParams->get( 'path_latex', 'c:/texmf/miktex/bin' ),
    $mambotParams->get( 'path_dvips', 'c:/texmf/miktex/bin' ),
    $mambotParams->get( 'path_convert', 'c:/imagemagick' ),
    $mosConfig_absolute_path . '/mambots/content/latex/tmp',
    $mosConfig_absolute_path . '/mambots/content/latex/cache',
    array(),
    array(),
    array()
    );

Next, add some packages to $\LaTeX$ compiling:

(/mambots/content/moslatex_build.php):

  •  function prepare($input) {
     return "\documentclass[10pt]{article}\n"
    . "% add additional packages here\n"
    . "\usepackage{amsmath,graphicx,pst-plot,pstricks}\n"
    . "\usepackage{amsfonts}\n"
    . "\usepackage{amssymb}\n"
    . "\usepackage{color}\n"
    . "\pagestyle{empty}\n"
    . "\usepackage{calrsfs}\n"
    . "\begin{document}\n"
    . "\begin{align*}\n"
    . $input
    . "\n\end{align*}\n"
    . "\end{document}\n";

And it works.