Extension:WikiTex
there is also a extension called (with uppercase x) Extension:WikiTeX 
This extension stores its source code on a wiki page. Please be aware that this code may be unreviewed or maliciously altered. They may contain security holes, outdated interfaces that are no longer compatible etc. Note: No localisation updates are provided for this extension by translatewiki.net . 
WikiTex Release status: unmaintained 


Implementation  Tag 
Description  Enter math inside $..$ 
Author(s)  Laszlo Csirmaz 
Latest version  wikitex (20080114) 
MediaWiki  1.7 
License  No license specified 
Download  Extension:WikiTex/Installation 
Translate the WikiTex extension if it is available at translatewiki.net  
Check usage and version matrix. 
Adding the <wikitex> ... </wikitex> tags for an easier entry of mathematical formulas.
Contents
Problems with the standard <math> tagEdit
 too much to type, error prone (<math>x</math> rather than $x$)
 slow to generate the result
 white background (rather than transparent)
 no proper vertical alignement
 smart syntax checker which knows better than I do.
While one can change formula background to transparent by hacking the helper function, it requires another round by the sloooow convert program.
What Extension:WikiTex offersEdit
 math text is entered between $ symbols
 fast turnaround (using plain TeX > dvipng)
 transparent background
 proper vertical alignment (almost)
 displayed formulas between $$ and $$
 user costumizable TeX definition files
CaveatsEdit
 no fancy things, all math is a picture
 unfriendly error messages (syntax error)
 easy littering: pictures of erased math text remain around
 possible formatting problems with new lines; certain extensions might not work properly (due to the recursive call of wiki formatting)
 tested on linux only
Parser extension tagsEdit
This extension adds two tags. The main additional tag is <wikitex> which indicates that from here math text is entered between $..$. Internally math text is wrapped inside <tex> tags, but this can also be used directly. The extension supports certain attributes, such as dpi=100 to make smaller images, or include="Math:Mycommands" to automatically include your TeX macros.
DocumentationEdit
Full documentation is in Extension:WikiTex/Documentation.
How to use itEdit
Use <wikitex> and </wikitex> to enclose the part of the page (maybe the all page) on which you want to use the usual math editing:
<wikitex> Let $Q$ be any finite set, and $\mathcal B=2^Q$ be the collection of the subsets of $Q$. Let $f:\mathcal B\rightarrow \mathbb R$ be a function assigning real numbers to the subsets of $Q$ and suppose $f$ satisfies the following conditions: :(i) $f(A)\ge 0$ for all $A\subseteq Q$, $f(\emptyset)=0$, :(ii) $f$ is monotone, i.e. if $A\subseteq B\subseteq Q$ then $f(A)\le f(B)$, :(iii) $f$ is submodular, i.e. if $A$ and $B$ are different subsets of $Q$ then $$f(A)+f(B)\ge f(A\cap B) + f(A\cup B).\eqno{(2)}$$ </wikitex>
Beware: formulas are typeset with plain TeX with some predefined commands (such as \mathcal or \mathbb above). LaTeX constructs do not work.
Formula numbersEdit
Displayed formulas might have formula numbers. They should come inside the $$ signs, and it should be the argument of the TeX macro \eqno{...}:
$$f(A)+f(B)\ge f(A\cap B) + f(A\cup B). \eqno{(2)}$$
Be default, formula numbers appear on the right of the formula (but can be on the left when changing the appropriate style), and are not part of the formula.
$$a_2^3$$
InstallationEdit
 You need the standard <math> tag enabled and working
 You need an external worker program which transforms plain tex files into pictures and returns certain status information.
 If your wiki was configured with math, then probably TeX was installed. Otherwise you need to install TeX as well.
 Install dvipng, a fast dvi bitmap converter program.
 Copy the supplied shell program, or something similar, into /usr/local/bin/texconvert, or change the name and/or location in WikiTex.php.
 Install the supplied WikiTex.php program into the extensions directory of your wiki.
 Edit MediaWiki:Common.css which sets how displayed formulas are shown.
 Edit MediaWiki:TexInclude which contains some standard TeX macros.
 Enjoy
Details a and source are in Extension:WikiTex/Installation.
See alsoEdit
 Extension:MathJax which enables common LaTeX and other formula delimiters.