Beta 3 of MacOS 10.14.4 Release for Testing
Apple has released the third beta version of macOS Mojave 10.14.4 to Mac users enrolled in the beta testing programs for system software. The developer beta is typically available first, with a public beta release available soon after.
MacOS Mojave 10.14.4 beta 3 likely has a primary focus on bug fixes and security enhancements. Several minor features are also included in the current beta versions, including some changes to Safari on the Mac and News app support for Canada.
For those who are enrolled the Mac system software beta testing program, MacOS 10.14.4 beta 3 can be found in the Software Update section of System Preferences.
iOS 12.2 beta is also currently a work in progress, though beta updates for that have not been released along with 10.14.4 beta 3.
Beta system software is generally intended for advanced users and developers only, but anyone can enroll in the public beta testing program. Technically anyone can enroll for an Apple Developer account to receive developer beta versions as well, but doing so requires an annual membership in the Apple Developer program.
Apple usually goes through a variety of beta system software builds before releasing a final version to the general public. Tracking beta releases can therefore be helpful to have a general idea of when a new system software update will be released, perhaps addressing some bug or security issue that users are experiencing.
Current stable builds of Apple system software include MacOS 10.14.3 (and a separate 10.14.3 Supplemental Update) for Macs and iOS 12.1.4 for iPhone and iPad.