Just a day after releasing a new set of developer builds for iOS 9 and OS X El Capitan, Apple today launched its public beta program for both upcoming operating systems. Apple had announced at WWDC last month that it would launch the public betas in July, and a new support document published yesterday regarding changes to two-factor authentication hinted a launch was imminent.
http://www.macrumors.com/2015/07/09/ios-9-os-x-el-capitan-public-betas/