XML question regarding special characters

[Zeljko Vrba <mordor@fly.srk.fer.hr>]

Hi!

I'm trying to design a "universal" markup that will be easy to convert both
to PDF and HTML. I've come to code and equations. I don't want to use
MathML and I want to output (and use in my documents!) verbatim TeX code of
equations to HTML. What worries me is the following:

I want to be able to write and run through Context XML processing:

<formula label="fm:whatever>
  x^{2} < y
</formula>

or, for typesetting computer programs:

<code>
  if((x&y) >= 3) {
    do_something();
  }
</code>

(this would translate to \starttyping\stoptyping)

How do I define XML environments that can handle XML special characters
(<>&, etc., I  don't know all of them..) gracefully? (i.e. so that I don't
have to type <code> if((x&amp;y) &gt;= 3) </code> and similar for formulas)

Thanks!