Apple has released another build of OS X Yosemite 10.10.3, both for developers, along with members of the AppleSeed public beta program.
Developers can get this latest build from the Apple Developer Center, or by going to the Updates section of the Mac App Store on a Mac already running the latest developer beta. There, developers can also find the latest Yosemite Recovery Update. AppleSeed testers can also download the latest build from the Mac App Store.
OS X 10.10.3 contains the new Photos for Mac app. The app will let you view, manage, and edit your iCloud Photo Library on your Mac, and will replace Apple's current iPhoto and Aperture applications when it launches to the public at some point this spring.
Source: Apple Developer Center