This is what I do. Most of my stuff degrades gracefully, but for the few things which can't (JS demos/game things), I generally do something like this:
<noscript>example.com is a HTML5/ES5/CSS3 3D graphics demo. Unfortunately, your user-agent doesn't seem to support ES5, sorry about that.</noscript>
Or you could phrase without all the academically correct technical buzzwords, so normal people who are your real audience will understand what you're trying to communicate. Like using "JavaScript" instead of "ES5" and "web browser" instead of "user agent".
> Or you could phrase without all the academically correct technical buzzwords, so normal people who are your real audience will understand what you're trying to communicate.
Normal people who are my real audience probably don't even know how to disable javascript, and most likely would enable it with no fuss if something looked broken.
