in theory you could use a font library with gd and perhaps some cgi to generate text on a specific font like www.dafont.com does.
However, if you notice the output from dafont is an image not a font. That's because fonts you see on your computer are local to your computer. So if you simply dont have a font you simply cannot see it.
However, actual HTML in a forced font is at least as far as I can see, undoable for now. But I dont think that will be the case too far into the future.