Paragraph about LaTeX equation editor
The current draft allows the intermixing of position (presentation) notations and content notations, as well as a "semantics" tag that allows for an apparently arbitrary piece of stuff to be attached to (what amounts to) a node in a tree. For example, the presentation of an integral with limits may be presented as an integral sign with sub/super-scripts and embedded dx somewhere. By contrast, the semantics for the same object may describe lower/upper- limits of integration and may explicitly mark the variable of integration "x".
If one agrees on a compact notation, one might wonder why SGML syntax is still needed: for what it is worth, there are applications that verify and process SGML syntax, and that conformance to the verbose version is required. Two vendors of programs mentioned below (WebEQ and TechExplorer) say they will be able to read and write MathML, and more are expected, including Equation editor EZMath, Amaya, and products from Design Science (Mathtype), Waterloo Maple, and Wolfram Research (Mathematica). You can find an update on the status of programs that implement some components of mathml. which is a nice discussion and a defense of TTH (Tex to HTML) by its author, Ian Hutchinson. This is a program to render TeX into html, including mathematics. It does a reasonably good job, and uses html itself. I found it worked rather well, at least on a sufficiently up-to-date browser. IT works fine on Netscape 4.6 on Windows NT without any downloading of Java (WebEQ does this) or the use of a plugin (MathExplorer requires this), or the replacement of your whole damned browser ( which is what Amaya frow W3C requires. ). The prospect of everyone using Amaya is pretty slim, but it works nicely for math, allowing one to see typeset material using CSSL, and it allows for coordination, moving into and around structures defined in MathML using XML. It totally ignores Scientific software the representation of semantics, which is intellectually the far more interesting part of the job, and deals solely with the the presentation. That is, it takes the part that is solved by TeX and other typesetting specifications, solves it once again in a particularly long-winded and clumsy way, and (at least to my thinking) violates the SGML spirit (namely that the SGML should represent the "meaning" or at least the structure of a document, and allow the viewer to impose a display representation). Here the XML dictates exactly the display, including font sizes, etc. Given that, Amaya still is kind of interesting in that it offers simultaneously a tree version and a displayed version of an expression, and the data can be selected and edited by pointing or swiping with a mouse in the window associated with either view. This is neat, even though it misses the major MathML point. Presumably it would be exhausting for W3C and its staff and volunteers to try to keep up with the Netscape or Microsoft browsers (and their installed base), as well as Java, which is not included at all. Amaya should be considered a proof of concept so as to insinuate its features into every browser. (Amaya is also an editor that can be used to create web pages.)