Mathematical notation has always presented a special problem for authors of web articles, since HTML provides only very limited mark-up for mathematics (mainly the tag for a variable, and the and tags for subscripts and superscripts. Here is a sample mathematical expression rendered with basic HTML:
y = a0 + a1x + a2x2
For an article with relatively simple mathematical notation, these basic HTML tags may be sufficient. If not, there are a couple of approaches that JOMA authors can use:
MathML, the Mathematics Markup Language is an XML language that provides a very complete specification of mathematical notation. MathML is an open source, W3C standard and is now supported by the Mozilla Firefox browser and by the latest versions of Internet Explorer on the Windows platform via the free the MathPlayer plug-in. Moreover, in keeping with the best practices discussed previously, MathML encodes the structure of the mathematics much more completely than previous mark-up languages (such as TeX). Because of this, mathematical expressions in MathML can be imported from one MathML-aware program (an HTML document, for example) to another (Maple, for example). On the downside, MathML is difficult to author without special editing tools (precisely because so much information is encoded), and MathML is not supported on older browsers. Without a doubt, however, MathML is the future of mathematics on the web. In spite of the difficulties, a major goal of JOMA is to promote and encourage its use.
Another approach is to convert mathematical expressions into small graphics (typically in the PNG or GIF format). The graphics can be created with special tools (such as MathType) or with special converters (such as TeX to HTML). Remember, however, that "best practices" would require alternate text-based descriptions of the mathematical expressions also (in TeX or MathML, for example), attached via the alt or title attributes of the tag.
For more information on writing mathematical expressions in HTML and in MathML, see Mathematics with Structure and Style