Apple has released the fourth developer beta for testing of what would become the third major software update to macOS Sierra since the last public launch. Considering that the previous macOS 10.12.3 betas did not introduce any new features, the newer software update seems to be much focused on fixing bugs and improving performance.

According to Apple's release news, the software update is expected to improve stability, compatibility and especially the security of user's Mac. It is notable that this update fixes a Safari bug which caused battery life issues during the MacBook Pro testing conducted by Consumer Reports.

Before launching macOS Sierra 10.12.3 beta, Apple first released the current official version of the operating system with macOS 10.12.2. The version included four new wallpapers,  graphics and System Integrity Protection fixes, Unicode 9.0 emoji, and removal of the time remaining estimate feature from battery status indicator.

The first developer beta was entered by macOS 10.12.3 on December 14 following the second beta on December 20 which was right before the holiday break. However, the third macOS 10.12.3 beta released earlier this week still struggled with bugs problem for MacBook Pro Touch Bar users. The bugs are hopefully sorted out in this release.

Made available by Apple since September, macOS Sierra is the latest Mac operating system. The innovative system includes Apple Pay for the web, Siri Support, Apple Watch auto unlocking, Universal Clipboard, improved iCloud Drive integration, Picture-in-Picture multitasking, and many other features that can be found in macOS Sierra roundup.

The macOS Sierra 10.12.3 beta 4 (build 16D30a) is now available for download via Apple's Developer Center or through the Software Update mechanism in the Mac App Store's Updates tab for Mac computers that have a prior Sierra beta installed.