Kexts and System Extensions — How macOS Drivers Have Evolved
macOS has been quietly retiring traditional kernel extensions in favour of safer alternatives. Here is what changed and why it matters.
Kernel Extensions, the Original macOS Driver
For most of macOS's history, third-party drivers shipped as kernel extensions, or 'kexts' — bundles loaded directly into the macOS kernel with full system privileges. They worked well, but they shared all the risks of any kernel-mode driver: a bug could crash the whole machine.
Kexts also made macOS more vulnerable to malware that could persist deep in the system. The OS vendor began tightening kext loading rules years ago, requiring user approval and notarisation before any new kext could load.
DriverKit and System Extensions
The OS vendor introduced DriverKit and System Extensions to move driver code out of the kernel and into safer user-space frameworks. These newer drivers run with restricted privileges, communicate with the kernel through tightly controlled APIs, and cannot bring down the system if they crash.
From the user's perspective, the experience is much the same: install a driver, approve it once, and forget it. Behind the scenes, however, the safety profile is dramatically better.
What This Means for modern Mac computers with custom silicon
modern Mac computers with custom silicon strongly prefer System Extensions and DriverKit. Loading a traditional kext on modern Mac silicon requires reduced security mode and a deliberate user opt-in — a clear signal that the OS vendor wants the kext era to end.
For most users, this transition is invisible. Vendors that still need driver-style functionality on macOS have largely migrated their products to the new frameworks already.
Quick Answers
Frequently Asked Questions
The questions readers send us most often on this topic.
Yes, but the OS vendor discourages them. New macOS releases require user approval and notarisation, and modern Mac silicon adds an extra security opt-in.
macOS's user-space driver framework, the modern replacement for traditional kernel extensions on macOS.
Probably eventually. macOS has been clearly signalling for years that the future is System Extensions and DriverKit.
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