I've hacked the phpwiki code to add a new
namespace
[[math: ]] so you can write formulas like [[math:a^2+b^2=c^2]] or
[[math:\sum_{n=0}^{\infty}\frac{1}{n}=\infty]].
The code will make TeX create an image (PNG) of the formula. Those
images will be cached, they will be created only once and will be
shared between articles. ( [[math:E=m c^2]] might be used on many
pages ).
That's almost exactly what I had in mind; only I think it would be
better for the back end to have to have a spearate process
communicating with the Wiki code over IPC--the "TeX server"--
which will take formulas and return images, out of a cache if
they've been rendered already, calling TeX to render them if needed.
The cache will be indexed by a hash function on a canonicalized
text of the expression.
The wiki end of this won't be hard. The other server is the real
work. I'm afraid I can't take on that project right now, but if
that server gets built, I'll be happy to call it.