6. Under the Hood

A number of other features--some visible to users, others not--will also appear in Firefox 4, including support for the WebM format for HD-quality video; 3D graphics via WebGL; elegant animations through the use of CSS3; and multitouch support.

Then, too, there's super-fast graphics acceleration with Direct2D and Direct3D on Windows, XRender on Linux, and OpenGL on Mac enabled by default on supported hardware.

7. Improved Security

With HTTP Strict Transport Security, or HSTS, sites can now make sure information is always encrypted, thereby preventing attackers from intercepting sensitive data. Previously, a hacker sitting in a Starbucks store, for example, could potentially watch Web surfers enter a bank's home page, which is not encrypted, and hijack them from there, Nightingale noted.