Raphael: vector graphics.
Browser support for everything from IE6 (really) to Android (post Honeycomb).
20kb gzipped Javascript.
Completely different thing from HTML5 <canvas>
.
Raphael has a low z-index, other things will appear in front of it, by default.
Can select by ID.
Can even use the JQuery selector.
Fonts
Can get fonts with Cufon. [Hmm. I think i'd avoid putting any fonts in here, a drawing program, and avoid Cufon in favor of @fontface anyway.)