Until recently, sitemaps were hand-drawn or script-drawn tree diagrams. Now browsers that support eXtensible markup language (XML) offer more elaborate sitemaps as a special feature. The newer sitemaps provide a hierarchical description of a site, written in the resource description framework (RDF), an XML application still being developed as a standard by the World Wide Web Consortium. For example, Netscape's Mozilla finds RDF sitemaps by looking for tags in your Web pages. This tag tells Mozilla to open the sitemap and then render the site diagram as part of the graphical display of the user agent. While sitemaps themselves may not be the niftiest things in the world, they do occupy a noteworthy position on the Web's timeline as one of the first implementations of RDF.