I am developing a web site that has to display plenty of advanced mathematics.

So far I have been using latex2html, but now I am looking for info about all special symbols and etc so that I can write the eqations directly in HTML.

latex2html is a wonderful convertor but it needs plenty of settings if you want to display things your way.

my question is - are there special characters in HTML that can cover all the symbols used in advanced mathematics?

No, there are not. This is all there is.
http://htmlhelp.com/reference/html40/entities/

I don't know what the best way to do this is. There's Unicode and MathML, but I suspect neither works so well in the real world. I'm afraid I don't know enough about this. Hopefully someone else can give you a better answer.

http://www.w3.org/Math/
http://www.alanwood.net/unicode/#links (scroll down to "Symbols" and you have 4 links concerning math there)

I don't really know... but Unicode is certainly not a "solution", since it's just a character set. The problem with maths is not the marks, but their positioning.

I'm not too clear what you mean by "advanced mathematics", but if you look at mathworld (e.g. http://mathworld.wolfram.com/CauchysInequality.html ) you'll see they use images. My guess is that this is the best way in practice for the time being.

MathML really does have advantages that other methods don't share -- things such as making the math accessible to those with blindness and other disabilities, making the math searchable, allowing the math to re-size when your readers re-size the text in the page, printing at full printer resolution, it's reusable (by pasting it into another app that understands MathML), etc. One of the downsides is that not all browsers can display MathML. However, the 2 "main" browsers can -- Firefox will display MathML without any help, and Internet Explorer can display the MathML with the aid of Design Science's free display engine, MathPlayer. That covers about 90% of all browsers in use today.

If you do decide to go with images, you can help your viewers by adding some descriptive alt text to the <img> tag. For example, if this is your expression:



One option is to write alt text that just describes in plain English what the equation is, like



A better option may be to include LaTeX as alt text, like



By using LaTeX, it makes the equations re-usable. If people viewing your site have MathType, they can copy the image, paste it into MathType, then use it like any other MathType equation.

So you can see there are plenty of options to choose from. The one that's best for you mostly depends on your audience.

Or both... a little link to the LaTeX maybe.

What about two verions? A MathML version and an image version? If MathML works for that many, it would be sad not to use it.

Actually that's a very valid point. A little extra trouble, but if you want both the advantages of MathML and the universal appeal of images, it's the only way to go. Here's an article that describes the process. Whether you follow all of the instructions on the page or not, the section on creating a "gateway page" is the part that talks about distinguishing one page from the other at load time. http://www.dessci.com/en/reference/webmath/mt_mp/default.htm