Based on the tags from this post.
Firefox 3 passes Acid 2 Test (eventually)
The latest nightly build of Firefox 3 passes the Acid 2 test. [...]
9 drawings done by an artist under the influence of LSD -- part of a test conducted by the US government during it's dalliance with psychotomimetic [...]
CSS Zen Garden
Two very nice submissions which weren't official designs!! Seems to be getting very difficult to get a design accepted as official these days. [...]
Why we need standards support in HTML email
Campaign Monitor call for an Acid Test for email clients. [...]