"Earlier this year, we reported on Mozilla’s effort to unify the look of its Web browser across platforms and device form factors. The organization combined its desktop and mobile design teams and began working on a new theme called Australis that promises to bring a fresh and consistent style to Mozilla’s browser lineup. Each individual port of Firefox will still conform with the appearance of the underlying platform, but there will be a number of shared design elements that are present across all platforms. One of those shared design elements is a gentle curve, which will appear in the navigation bar on mobile versions and in the tab bar on the desktop. As the Australis mockups have long depicted, the new theme will bring some significant changes to the style of the tab bar. The active tab will be displayed with curved edges and a background that converges with the navigation bar. The inactive background tabs will be rendered without a background, as if overlaid on the titlebar of the window." - Miguel Caetano from Bookmarklet