Introduction
As mentioned during the Mozilla Summit and recent MathML meetings, progress has recently be made to the way mathematical equations are handled on Wikipedia. This work has mainly be done by
the volunteer contributor Moritz Schubotz (alias Physikerwelt),
Wikimedia Foundation's developer Gabriel Wicke as well as members of
MathJax.
Moritz has been particularly involved in that project and he even
travelled from Germany to San Francisco in order to meet MediaWiki developers and spend one month to do volunteer work on this project.
Although the solution is essentially ready for a couple of months, the
review of the patches is progressing slowly.
If you wish to speed up the integration of what is probably the most
important improvements to MediaWiki Math to happen, please read
how you can help
below.
Current Status
The approach that has been used on Wikipedia so far is the
following:

Equations are written in LaTeX
or more precisely, using a specific
set of LaTeX commands accepted by
texvc. One issue
for the MediaWiki developers is that this program is written in
OCaml and no longer maintained, so they would like to switch to a more
modern setup.

texvc calls the LaTeX program to convert the LaTeX source into PNG images and this is the default mode.
Unfortunately, using images for representing mathematical equations
on the Web
leads to classical problems (for example alignment or rendering quality
just to mention a few of them)
that can not be addressed without changing the
approach.

For a long time, registered users have been able to switch to the MathJax mode thanks to the help of nageh, a member of the MathJax community.
This mode solves many of the issues with PNG images but
unfortunately it adds its own problems,
some of them being just unacceptable for MediaWiki developers. Again, these issues are intrinsic to the use
of a Javascript polyfill and thus yet another approach is necessary for
a longterm perspective.
 Finally, registered users can also switch to the LaTeX source mode, that is only display the text source of equations.
Short Term Plan
Native MathML is the appropriate way to fix all the issues regarding the display of mathematical formulas in browsers. However, the language is still not perfectly implemented in Web rendering engines, so some fallback is necessary. The new approach will thus be:
 The TeX equation will still be edited by hand but it will be
possible to use a visual editor.
 texvc will be used as a filter to validate the TeX source.
This
will ensure that only the texvc LaTeX syntax is accepted and will avoid
other potential security issues.
The LaTeXtoPNG conversion as well as OCaml language will be kept in
the short term, but the plan is to drop the former and to replace the
latter with a a PHP equivalent.
 A LaTeXtoMathML conversion followed
by a MathMLtoSVG conversion will be
performed serverside using MathJax.
 By default all the users will receive the same output (MathML+SVG+PNG) but only one will be made visible, according your browser capabilities. As a
first step, native MathML will only be used in Gecko
and other rendering engines will see the SVG/PNG fallback ; but the goal is to progressively drop the old PNG output and to move
to native MathML.
 Registered users will still be able to switch to the LaTeX source mode.
 Registered users will still be able to use MathJax clientside, especially if they want to use the HTMLCSS output. However, this is
will no longer be a separate mode but an option to enable. That is, the MathML/SVG/PNG/Source is displayed normally and progressively replaced with MathJax's output.
Most of the features above have already been approved and integrated in the development branch or are undergoing review process.
The main point is that
everybody can review the patches on Gerrit.
If you know about Javascript and/or PHP, if you are interested in math
typesetting and wish to get involved in an important Open Source project
such as Wikipedia then it is definitely the right time to help
the MediaWiki Math project. The article
How to become a MediaWiki hacker is a very good introduction.
When getting involved in a new open source project one of the most
important step is to set up the development environment. There are
various ways to setup a local installation of MediaWiki but
using
MediaWikiVagrant might be the simplest one: just follow the
Quick Start Guide and use
vagrant enablerole math
to
enable the Math Extension.
The second step is to create a WikiTech account and to set up the appropriate
SSH keys on your MediaWikiVagrant virtual machine.
Then you can check the Open Changes,
test & review them. The Gerrit code review guide may helpful, here.
If you need more information, you can ask
Moritz
or try to reach people on the
#mediawiki
(freenode) or #mathml
(mozilla) channels. Thanks in advance for your help!