The macOS Mojave 10.14.4 update is another hefty one, amounting to 2.5-2.8 GB of download, which installs over 80,000 items taking over 6 GB of disk storage. Apple has for once provided quite detailed release notes, as well as notes on the security fixes, so we know a great deal more about this update than any other since El Capitan or before. Even so, there’s a lot more detail to find.

There are EFI firmware updates apparently for all Mac models, which I have now entered in my article listing current EFI firmware versions.

Among the major apps to be replaced are:

• App Store (still 3.0), which fixes an issue preventing update to the latest versions of some Apple apps.
• Automator (2.9) and most of its Actions.
• Books (1.18).
• Calculator (still 10.14).
• Calendar (still 11.0).
• Contacts (still 12.0).
• FaceTime (still 5.0), which fixes another vulnerability.
• iTunes (now 12.9.4), which shows more editorial highlights, and adds support for Second Generation Airpods.
• Mail (now 12.4).
• Maps (2.1), which adds Air Quality Index maps for some countries.
• Messages (still 12.0), which has improved quality audio recording.
• News (now 4.2), which adds support for the new Apple News+ subscription service, where available.
• Photos (still 4.0).
• Preview (10.1).
• QuickTime Player (10.5).
• Safari (now 12.1 14607.1.40.1.4), which adds adds Dark Mode support for websites which offer specific support for it, warns when insecure pages are loaded, has Intelligent Tracking Prevention to replace the Do Not Track standard to protect against cross-site tracking, and more.
• Siri (still 1.0), which fixes a vulnerability which could initiate a Dictation request.
• TextEdit (still 1.14).
• Time Machine (1.3).
• Activity Monitor (still 10.14), which has better support for eGPUs.
• ColorSync Utility (4.14.0), which appears to be a great improvement with many issues fixed.
• Console (still 1.1).
• Disk Utility (18.0).
• System Information (still 10.14).

In the system folders:

• /bin and /sbin have many replacement tools.
• Apple’s Druk fonts in iLife support are replaced with new ones.
• Most of the Marzipan support in /System/iOSSupport is replaced.
• Most of the apps and other tools in /System/Library/CoreServices are replaced.
• Pretty well all kernel extensions are replaced.
• System fonts replaced include Apple Color Emoji, SFNSRounded and SFNSSymbols.
• Most if not all Frameworks and Private Frameworks are replaced.
• Most if not all Preference Panes are replaced.
• All QuickLook qlgenerators are replaced.
• Pretty well the whole of /usr is replaced too.

This update should also improve the reliability of USB audio devices used with Mac mini 2018, MacBook Air 2018, and MacBook Pro 2018 models; it should correct default display brightness settings for the MacBook Air 2018, resolve Wi-Fi connection issues generally, and fix problems with external displays connected to the Mac mini 2018.

APFS has been updated from version 945.241.4 in 10.14.3 to version 945.250.134, which is the smallest increment so far in any macOS update, and comes with new versions of each of its tools.

TCC’s AllowApplicationsList.plist has been updated from 15.0 to 16.0.

A major internal change is that macOS 10.14.4 now itself includes the ‘glue’ for Swift apps, which no longer need to include their own ‘glue’ files to work with system frameworks. This won’t have much immediate impact, but will lead to improvements in the long term, as I have explained here. However, at present there may be some glitches with command tools written in Swift and built with the new version of Xcode, 10.2. As some apps embed their own command tools for private use, this could become an issue with users: I will bring further details and news about this as it develops.

Standalone installers are available:
10.14.4 delta is here,
10.14.4 Combo is here,
Sierra Security Update 2019-002 is here,
High Sierra Security Update 2019-002 is here.

These should be the last system updates until late May or early June now, when 10.14.5 is most likely to ship.