Apple released a new version of OS X Yosemite to developers



From MacRumors:

The update can be downloaded from the Mac App Store or through the Mac Developer Center. Apple has also released iTunes 12.0, Yosemite Recovery Update 1.0, OS X Server 4.0 Developer Preview, and Apple Configurator 1.7 beta. iTunes 12 includes an "elegant new design" and introduces support for Family Sharing, a feature first announced during WWDC. The update also includes improved playlists and a redesigned Info Window.

  Apple Releases OS X Yosemite Developer Preview 4