MacRumors reports that Apple today released the fifth beta of OS X El Capitan to developers for testing purposes

Today's update is available through the software update mechanism in the Mac App Store and through the Apple Developer Center. It is not clear if this update will add any outward-facing changes to El Capitan, as the past few betas have focused on under-the-hood performance improvements and bug fixes to optimize the operating system ahead of its public release. We'll add new features and bug fixes in beta 5 to this post should any tweaks be discovered. As an update complementary to OS X Yosemite, OS X El Capitan builds on the myriad features introduced last year. Behind-the-scenes improvements in El Capitan make a number of apps and processes on the Mac faster, and the introduction of Metal makes system-level graphics rendering 40 percent more efficient.

  Apple Seeds Fifth OS X El Capitan Beta to Developers