When I first was introduced to the world wide web back in 1993, I immediately decided that I would build a web site that displayed the equations and tables in NACA Report 1135. Since I was pretty good with TeX, I figured it would be a simple project, because I assumed that there would be math tags that would let me write equations much as I did with with TeX. Wrong!
I did manage to put about half a dozen equations on a page through the laborious process of transforming them into GIF images. But, whenever we got a new version of a browser, the text and images would move around and look quite different from the way I wanted. Worst of all, the parts of the math that were rendered in smaller font sizes (such as subscripts or exponents) were always hard to read and even if you had some zoom control, it just looked "blocky" when you enlarged the math. I lost interest at that point although I always knew that there was a great potential for science and engineering education if we could just work out the details.
It has taken fifteen years, but we are finally on the verge of being able to serve pages with readable mathematical expressions and not have hundreds of image files with pictures of the mathematical expressions. MathML, which stands for Mathematical Markup Language, just as HTML stands for HyperText Markup Language, is the key to it all. I won't try to explain it all here, but will give you several links that will help you get started.
If you simply want to read other peoples pages, you need a web browser
that supports MathML and you need the appropriate fonts installed on your
system.
Right now, the only browser that seems to work is
Firefox.
To learn more, the best starting point is the
World Wide Web Consortium (W3C)
MathML page.
From this page, there are links to many helpful pages to get
you started. And to help you find the fonts.
There is a book by Pavi Sandhu, The MathML Handbook, published
by Charles River Media.
If you want to create your own pages with MathML, you will need help. There are at least four ways to prepare your pages
I have used all four techniques. Personally, I am using #3 right now more than any other because I am making a backup version of each page as a PDF for those who do not want to upgrade their browsers. I can go from TeX to MathML and TeX to PDF in almost one operation. You can learn a lot by viewing an interesting page written with MathML and selecting 'View Page Source'. [That also applies to HTML].
I used to have a link to an IBM product called TechExplorer. But, it always shows up as a broken link and Google can't find it anymore, so it must have ridden off into the sunset.