MathML is a low-level specification for mathematical and scientific content on the Web and beyond.
Here is an example of Presentation MathML: and another:
|XML Entity Definitions||REC||WD|
|Units in MathML||NOTE|
|Arabic mathematical notation||NOTE|
|Structured Types in MathML 2.0||NOTE|
|Bound Variables in MathML||NOTE|
|A MathML for CSS Profile||REC|
What is MathML teaches you how to create your first equation and to understand the base constructs of MathML.
Of course, nearly all software has bugs. And some programs are further ahead implementing MathML 3 than others.
The <email@example.com> mailing list is the place for discussing the further development of MathML. The MathML working group also uses that list for most discussions. Everybody can subscribe (or unsubscribe, or see instructions.)
The Math Working Group is one of the oldest W3C Working Groups, started in 1997. You can learn more details about its mission in the Working Group Charter.
If you work for a W3C member organization, you can also join the working group.