Firefox 1.5 developer highlights:

"Firefox 1.5 Beta 1 is out, and is the most exciting browser release in a very long time. It comes with the Gecko 1.8 rendering engine, which includes a ton of interesting new features. New in this version (unless you've been tinkering with the Deer Park series):

SVG
Canvas
CSS3 Columns
JavaScript 1.6
Let's take a look at these in turn."

(Via Simon Willison's Weblog.)