On Monday, October 28th, Apple released the macOS 15.1 update.  And, with that update, Apple has ratcheted up their war on "sideloading" by completely disabling the ability to run unsigned macOS software.

And signing software, of course, requires an Apple Developer Connection subscription.  Which, for most people, is a costly thing.

Every Few Months, A Little Less Freedom

Just a little over one month ago (September of 2024), the initial release of macOS 15.0 brought with it a new round of restrictions on running non-signed (also called "non-notarized") applications.  With 15.0, users could still run non-signed software... but they needed to jump through a few extra hoops by openning the System Settings and manually enabling each application they wanted to run.

This change made running unsigned software on macOS a bit more annoying -- additional steps to do something that used to be a simple "double click on the darned icon" process.  Annoying, to be sure.  But, luckily, all software could still be run.

That all changed -- less than 45 days later -- as Apple released the 15.1 update to macOS, which included the removal of the "Click around in System Settings" option to allow unsigned apps to run.

Now, in 15.1, when you attempt to run a non-notarized piece of Mac software, you will be greeted by a simple error message: "The application 'Finder' does not have permission to open '(null)'."

No option to run the software whatsoever.  Effectively banning all non-signed software (such as those developed by a hobbyist).

The War on Sideloading Continues

This isn't exactly a surprising move by Apple.  Over the last few years, all of the Big Tech operating system companies (Microsoft, Apple, and Google) have pushed -- with increasing intensity -- to lock down what software users are allowed to run on their computers.

Increasingly restrictive "application signing" systems, and the removal of "features" which allowed non-signed applications to run, have been a stated goal of all three corporations.

All in the name of a war on, what Big Tech has termed, "Sideloading".

What is "Sideloading", you ask?

"Sideloading" is most simply defined as "The act of installing software on a real computer."  And Apple, Google, & Microsoft are determined to stop people from doing that.

These companies haven't exactly been quiet about their goal to stop people from installing software on their computers (outside of approved, heavily restrictive mechanisms).  Back in 2021, Apple published a whitepaper entitled "Building a Trusted Ecosystem for Millions of Apps - A threat analysis of sideloading".

That's right.  Apple considers you having the freedom to install whatever software you want on the computer you own -- something every real computer (including those made by Apple) have done since the dawn of Personal Computing -- to be a "threat".

With macOS 15.1, Apple is taking significant steps to neutralize that "threat".

No software freedom for you.

The Last Workaround

As of now -- with macOS 15.1 -- there remains one final way to work around these draconian and artificial restrictions.

To do so requires the complete disabling of "Gatekeeper", the system which verifies downloads and restricts the running of non-signed applications.

This can be done via a fairly simple terminal command run as root:

sudo spctl --master-disable

However, it should be noted that with Apple's ever increasing requirements of application "notarization" -- and increasing reliance on the Mac App Store for software distribution (which ties into Gatekeeper) -- the full disabling of "Gatekeeper" seems likely to cause issues going forward with "Apple approved" methods of installing software.

Likewise, at Apple's current rate of attacks against "sideloading", the ability to turn off Gatekeeper may not be long for this world at all.

Don't Laugh, Google & Microsoft Users

While the news, today, is focused on Apple (their fight against the most basic freedoms of computing -- the ability to run software)... both Microsoft and Google have made it clear that they are all in on the war against sideloading.

Case in point: Google is migrating Android software away from "APK" application packages... to the far more restrictive "AAB" application bundles.  Microsoft, likewise, is pushing for a reliance on their online store.

So users of Android, ChromeOS, & Windows shouldn't laugh.  You're next.

Users of a variety of open source, alternative operating systems (such as Linux, BSDs, and many others), however, can laugh all they want.

No Ctrl-C's were harmed in the making of this post.