This is a sample file that
<A HREF="client2.cgi">runs a script</A>
on the <I>client</I> that, if it can, 
opens an <CODE>xterm</CODE> window.

<P>

The point here is that, in addition to
the way you can set up your preferences
so that files with certain extensions 
will launch a corresponding helper app,
that's not the only way to launch one.
But, you do have to have certain tools
ready to be launched in order for me
to do this, which is not too practical
in a distance-learning setting, where
everyone has their own unique set-up.  
But I did want you to know it was possible...