OS X Yosemite

OS X 10.10 "Yosemite" is a version of Mac OS X, released on October 16, 2014. It was announced at the 2014 WWDC, and is currently available for free download from the Mac App Store for all users. Yosemite is perhaps the largest change to Mac OS since the release of 10.0 itself, with a completely redesigned Aqua UI inspired by the translucent "Glass" design of iOS 7, new icons, Continuity, Spotlight 2, and other large-scale changes.

New design
Apple has redesigned OS X Yosemite. It is still called Aqua. The look is now more flat, but still retains some original Aqua look to make it more user friendly. Apple has also introduced transparancy. Everything underneath is blurred like in Windows Aero. The sidebar of the finder is transparent. The topbar in Safari shows whats underneath. Menus are transparent too.