Here some helpful tips about this document. Fact for OS and browser:
Object of the document is its content, not the representation. If a browser is unable to diplaya site, try an other. Please don't inform the webmaster. It could happen, that XML is used. In this case the browser is responsible for the correct representation. There is no test of any plugins.
For XML / MathML it is a good idea to visit "w3c.org". All examples of this document are at most elementary.