Ars Technica takes a look at the fourth beta of Firefox 4

Mozilla has announced the availability of the fourth Firefox 4 beta release. The new beta brings some extremely significant new features that have been gestating in Mozilla's labs, including built-in synchronization functionality and a sophisticated new tab management system.

Tabs have arguably had a major impact on how users operate Web browsers, but the concept hasn't scaled very well as browsing habits become more complex. Mozilla devised a compelling solution with its Tab Candy concept, which allows users to arrange groups of tags in spatially-organized collections. Mozilla's experimental implementation of Tab Candy has matured swiftly and is going to be fully integrated in Firefox 4. It's available for testing in the new beta release, though it's said to not be fully feature-complete yet.

  Hands-on: Firefox 4 beta 4 brings Tab Candy and Sync