Originally Posted by www.webstandards.org/action/acid3/

Acid3 is the third in a series of test pages written to help browser vendors ensure proper support for web standards in their products.

Acid3 is primarily testing specifications for “Web 2.0″ dynamic Web applications. Also there are some visual rendering tests, including webfonts.

Here is the list of specifications tested:

- DOM2 Core
- DOM2 Events
- DOM2 HTML
- DOM2 Range
- DOM2 Style (getComputedStyle, …)
- DOM2 Traversal (NodeIterator, TreeWalker)
- DOM2 Views (defaultView)
- ECMAScript
- HTML4 (<object>, <iframe>, …)
- HTTP (Content-Type, 404, …)
- Media Queries
- Selectors (:lang, :nth-child(), combinators, dynamic changes, …)
- XHTML 1.0
- CSS2 (@font-face)
- CSS2.1 (’inline-block’, ‘pre-wrap’, parsing…)
- CSS3 Color (rgba(), hsla(), …)
- CSS3 UI (’cursor’)
- data: URIs
- SVG (SVG Animation, SVG Fonts, …)