<a href="http://sbml.org/">Systems Biology Markup Language (SBML)</a> is a mixed bag as an example for a handler. On the one hand, it appears to be very rich and capable of describing models that are way too complex to be desribed via a program. On the other, sometimes it describe chemical reactions or process that have relatively succinct notational descriptions that could be coverted to words. Eg, see<br>
<a href="http://sbml.org/Image:Sbml-simple-reaction-example.jpg">http://sbml.org/Image:Sbml-simple-reaction-example.jpg</a><br><br>I don't know enough about biology or SBML to say whether this is normal or an exceptional case. There seem to be quite a number of piecies of software that make use of it.<br>
<br><br><br><a href="http://cml.sourceforge.net/main.html" id="cml-info">Chemical Markup Language</a> (CML) looks very promising as an example handler. There is at least one applet viewer for web pages (which has no keyboard navigation I could find. It is called JChemPaint and here's a page on embedding it in a web page (mostly just how to embed an applet):<br>
<a href="http://apps.sourceforge.net/mediawiki/cdk/index.php?title=JChemPaint_Inside_Webpages">http://apps.sourceforge.net/mediawiki/cdk/index.php?title=JChemPaint_Inside_Webpages</a><br><br>Here's a demo page which kind of shows the navigation/interaction possibilities (but isn't accessible as far as I can tell).<br>
<a href="http://cdk.sourceforge.net/jcpapplet/ViewerApplet.html">http://cdk.sourceforge.net/jcpapplet/ViewerApplet.html</a><br>Also, I think that JCehmPaint can read several formats besides CML, and in the above example, it appears to be reading a .mol file which is not part of CML AFAIK.<br>
<br> Neil<br>