Apple today seeded the second beta of OS X 10.10.4 to developers, approximately a week and a half since releasing the first 10.10.4 beta and nearly three weeks after releasing OS X 10.10.3 with the Photos for OS X app to the public. Alongside the new developer beta, Apple also released the first public beta version of OS X 10.10.4. Developers can download the new beta through the Software Update mechanism in the Mac App Store or through the Mac Developer Center. OS X 10.10.3 introduced several consumer-facing changes including the new Photos for OS X app, a redesigned emoji picker, new diversified emoji, and more, but OS X 10.10.4 appears to be an under-the-hood update that brings performance enhancements and bug fixes. The first two updates to OS X Yosemite, OS X 10.10.1 and OS X 10.10.2 were also minor behind-the-scenes updates that improved performance through bug fixes and enhancements.