What is the Apple Beta Software Program?
The Apple Beta Software Program lets users try out pre-release software. The feedback you provide on quality and usability helps us identify issues, fix them, and make Apple software even better. Please note that since the public beta software has not yet been commercially released by Apple, it may contain errors or inaccuracies and may not function as well as commercially released software. Be sure to back up your Mac using Time Machine and your iOS device with iTunes before installing beta software. Install only on non-production devices that are not business critical. We strongly recommend installing on a secondary system or device, or on a secondary partition on your Mac.
On its website Apple announces :
Help make the next releases of iOS 9 and OS X El Capitan our best yet. As a member of the Apple Beta Software Program, you can take part in shaping Apple software by test-driving pre-release versions and letting us know what you think.
For whom? For what?
As a member of the Apple Beta Software Program, you’ll be able to enroll your Mac or iOS device to access the OS X and iOS public betas, as well as subsequent updates. Each public beta comes with a built-in Feedback Assistant app that appears in your Dock on your Mac and on the second page of your Home screen on your iOS device. When you come across an issue that needs addressing, send your report directly to Apple with Feedback Assistant.
How do I get the public betas?
Who can participate?
The Apple Beta Software Program is open to anyone with a valid Apple ID who accepts the Apple Beta Software Program Agreement during the sign-up process. If you do not have an Apple ID, you can create one now.