A font constructed entirely by CSS. It is, essentially, a programmatic realtime typeface. I love how it degrades for older versions of IE:
It’s not what I’d consider practical for production use. Still, CSS Sans is a hell of a demonstration of how far CSS has come since Microsoft shipped Internet Explorer 3 in 1996, which was first browser to implement some of the CSS1 spec (CSS v1 was not yet a W3C recommendation).