This is the fifth beta of macOS 10.14.6 which adds a host of new bug fixes and performance improvements to the Mac before Apple goes all-in on macOS Catalina this fall.
Registered developers can download macOS 10.14.6 beta 5 from the Apple developer portal. It can also be installed through the Software Update options in the Apple menu on your Mac if you have the previous beta installed.
macOS 10.14.6 beta 5 comes just one week after Apple seeded the previous beta to developers along with iOS 12.4 beta 6 that brings Apple Card support to iPhone. The software update doesn’t contain any major UI changes or new features and mostly focuses on under-the-hood changes.
This will likely be the last macOS Mojave update before Apple moves onto macOS Catalina. Developers have already received three beta builds of macOS Catalina this summer. That update contains some huge improvements, like Project Catalyst which lets developers port their iPad apps to the Mac. It also lets you use an iPad as a secondary display on some Macs and brings some updated apps with it too.
Apple is expected to release the last macOS Mojave update this summer while macOS Catalina is set to launch to the public this fall.