The real issue here (for me at least) is
rendering equations within an HTML document. There are
several tools available which can do that with different
trade-offs. The most popular method is to write the
equations in a LaTeX document, process it, and then hoik
the equations out of the resulting DVI file somehow
(typically using dvips and a postscript to
gif converter), and display them on the web as gifs. The
big disadvantage with this is that you get an awful lot of
gifs, and the conversion is rather inefficient.
All this hassle should become irrelevant once we get browsers which can render MathML directly.
There are reviews of the problems, and some of the tools, in articles Maths Typesetting for the Internet, and Comparative Review of World-Wide-Web Mathematics Renderers.
LaTeX2HTML is the granddaddy of these translators -- it parses the LaTeX using Perl, and spits out HTML, turning maths into gifs. It's very robust by now.
John Walker's textogif is a Perl program which orchestrates the various tools to do the conversion via postscript, once you've generated the DVI file. It works, but it's terribly slow, which was the motivation for this program.
TeX4ht (TeX for Hypertext) uses TeX's own parser, but still produces equations as gifs. TeX4ht can also emit MathML from LaTeX. The TeX4ht documentation has a useful collection of resources. There's an alternative location for TeX4ht at TUG.
tth:
TeX to HTML translator (manual).
tth translates LaTeX maths directly to HTML,
with remarkable success and astonishing speed, and with
good failure strategies. It works very sweetly, but (a)
requires you to tweak your browser to have it map the
symbol font appropriately, and (b) the resulting HTML
can't be printed legibly. From the same source is TtHMML,
which translates (La)TeX to HTML plus MathML.
nDVI is a DVI viewer plugin for Unix Netscape. This addresses the problem at the client end.