On Wednesday, Apple released both developer and public-tester versions the fourth beta for its next current-release update
for OS X and iOS, and a developer-only fourth beta for tvOS. Developers are also expecting to gain access to a second beta for the major upgrades to these and watchOS in the near future, as it has been two weeks since the first beta
was released at WWDC. The latest updates -- iOS 9.3.3, OS X 10.11.6, and tvOS 9.2.2 -- are focused on bug fixes, along with security and performance enhancements, as usual.
This fall, the company will release macOS Sierra (10.12), iOS 10, tvOS 10, and watchOS 3, which all have major new features and other changes, but at present those betas are for developer accounts only, and carry a high risk of bugs or stability issues (though reports from developers indicate that they are presently more usable than is normally the case at this point in the major-upgrade development cycle). There will be a public beta program for the macOS and iOS platform upgrades at some point next month, with the final release expected to accompany new hardware in the fall, such as the "iPhone 7."
Developers wishing to obtain the latest minor updates can access them through the Mac or iOS App Stores under their registered developer accounts, or through Apple's developer portal on its website. The tvOS beta is obtained the same way, and requires developers to connect the fourth-generation Apple TV to the computer through a USB-C to USB-A cable to obtain the update via iTunes. The final release of the tvOS update will be available to end-users directly through the Apple TV.