Apple has released a new beta version of OS X 10.11, iOS 9, and WatchOS 2 to the developers for testing purpose:
Apple Seeds Second iOS 9 Beta to DevelopersNew OS X 10.11 / iOS 9 / WatchOS 2 Betas
Apple Seeds Second OS X 10.11 El Capitan Beta to Developers
Apple Seeds Second WatchOS 2 Beta to Developers