The WebTV Dialect

The set-top box that put the web on televisions had its own HTML tags, including one that drew a live waveform of the sound it was playing.

In 2026: Dead. WebTV, later MSN TV, rendered on one appliance and invented markup to match it: audioscope drew an oscilloscope of the current audio, blackface set double-weight bold, and shadow drew drop-shadowed text. No desktop browser ever knew any of them, so all three sit inert below, a whole dialect for a machine almost nobody kept.

Where it came from: WebTV proprietary HTML extensions, WebTV Networks, 1996 onward, later MSN TV. Documented in the WebTV HTML reference. Wikipedia ↗

<!-- Tags that existed only on the WebTV set-top box -->

<!-- A live oscilloscope of the playing audio -->
<audioscope width="200" height="80" leftcolor="#00ff00" rightcolor="#ff0000">

<!-- Double-weight bold -->
<blackface>This was extra bold on a television in 1997.</blackface>

<!-- Drop-shadowed heading -->
<shadow><h2>Shadowed Heading</h2></shadow>

<p>On a desktop browser, none of the three tags above does anything.</p>