General

Here some helpful tips about this document. Fact for OS and browser:

id ad anum mihi preterit.

The following points should be red if there are problems with sites and/or programming languages:

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.
Java

Really Java - not JavaScript. To use the downloaded programs a JSE.1.4.x is the minimum. Only run time environment is not enough. Also the API-Doc is useful to understand the source code.

For XML / MathML it is a good idea to visit "w3c.org". All examples of this document are at most elementary.