There are plenty of possibilities to embed mathematical formulas into webpages. Besides JSMath and several possibilities to include LaTeX-Generated png’s into Websites there is MathML – which should have been preferrable, but just didnt find broad usage.
I just read that there is a collection of Math-GIFs for mathematical symbols.
I dont really know whats the purpose of the latter. Making Formulas visible inside HTML is a problem which is not properly solvable. But for small formulas, you will find a Unicode Character for most of the things you want to express – just look at the plenty of character tables. Embedding these in HTML is not harder than embedding a GIF. Of course, with Unicode, you are bound to a linear notation. But to express small formulas, that is more than enough.
For anything else, I would still prefer LaTeX-Rendered PNG’s with LaTeX-ALT-Strings. That is, because even a blind person should be able to read it – at least with enough efforts, they can interpret the LaTeX-ALT-Strings. Of course, even for this, MathML would be the better choice. But LaTeX has spread. So well, why not use it for formula notation. Even inside HTML. Its a compromise. Its not perfect, but its good enough.