[codingdave]

Yeah, it is - not to the level people envisioned years ago where people made up their own tags and found a blend of XML and HTML, but it absolutely is in place for more meaningful HTML. We have tags that tell you the purpose of content - header, nav, section, article, footer, etc. Those tags are read by screen readers and other accessibility tools, and do bring semantic value to those readers.

[simongray]

Those things are semantic HTML elements, not the semantic web. The semantic web does have some HTML integration though, e.g. RDFa.