Latest HTML5 features allow you to create dialogues and popovers declaratively (just HTML attributes and some CSS to style it), rather than needing a giant bundle of JavaScript. Less JavaScript on web pages is always a good thing, and using built-in HTML features is good for accessibility as well. Here’s a blog post from David Bushell on how its done.
(Via What’s !important #6: :heading, border-shape, Truncating Text From the Middle, and More | CSS-Tricks)
