Apple is now on its third cycle of developer betas for its milestone operating system releases, with new builds of iOS 13, iPadOS 13, watchOS 6, tvOS 13, and macOS 10.15 Catalina now available for testing by program participants.
The latest builds can be downloaded by developers in the beta-testing scheme via the Apple Developer Center, or as an over-the-air update for hardware already using earlier beta builds. A public beta version of the releases is expected to start arriving soon, and will be available through the Apple Beta Software Program website.
The latest batch of builds arrives two weeks after the second round, and four weeks after the operating systems were originally unveiled at WWDC.
Apple is also operating a second set of betas for a more immediate release than the milestone iterations, covering iOS 12.4, tvOS 12.4, watchOS 5.3, and macOS 10.14.6.
Both AppleInsider and Apple itself strongly recommend users don't install the betas on to "mission-critical" or primary devices, as there is the remote possibility of data loss or other issues. Instead, testers should install betas onto secondary or non-essential devices, and to make sure there are sufficient backups of important data before updating.