Some relevant links

•  http://bioportal.bioontology.org/
•  Texai project download page Useful RDF for expressing English (including lexicon, grammars)

• About serialization (RDF/XML) --> this is integrated to StateOfPerlAndRdf.

Below is a bookmarklet that adds various semantic information to a page you browse and highlights those key terms.
Currently, it uses  whatizit to recognize terms, and embeds aTag data within a "<dbcls:atag>" tag.

[javascript:(function(){var%20d=document;var%20s=d.createElement('script');s.id='DBCLS_annot';s.src='http://purl.org/togodoc/annot2.js';d.getElementsByTagName('head')[0].appendChild(s);})()]