I thought I'd bring up this idea again since it might be easy to
implement with the new codebase.
If you put text such as [$\int_{x=0}^\infty x^2 dx$] in Wiki, upon
saving the article, TeX will be called and translate the formula into
an image, and store the image on the server and its name in a database
indexed with the formula text. When the Wiki page is presented, the
image is inlined (and an alt attribute containg the formula text
added). When the page is later edited and saved again, the system
first checks whether an up-to-date image of the formula already
exists; if not, TeX is called to regenerate it.
This would make mathematicians, computer scientists, physicists and
chemists happy. TeX includes a package for typesetting chemical
structure formulas and another one for quite general labeled diagrams
and trees. There's also a TeX package which allows to typeset musical
notes and another one for chess positions.
The concept could be expanded to other programs which can produce
graphics on-the-fly based on a textual description. This includes
gnuplot (graphs of functions) and maybe packages such as GD,
imagemagick or even GIMP.
Axel