If you are one of those who has signed up to test the public betas of Mojave: welcome. I think that you’ll come to enjoy this, as Mojave is promising to be one of Apple’s better releases of macOS.

Testing beta releases of macOS is always a bit nail-biting. Before you install the beta, step carefully through Apple’s recommendations. Ensure that the Mac on which you’re going to install Mojave is not one that you need to be able to use at all times. Betas can always do worrying things, and when you’re in a rush you don’t want to be trying to revive a frozen Mac which you need to work on.

Before you install Mojave, make sure that there is nothing of importance, or irreplaceable, on that Mac. Some betas have a tendency to wipe disks, or crash so badly that you have to erase the startup disk and start again.

You should also ensure that you’re ready to resuscitate your Mac, should things go wrong: do you know how to reset the SMC, zap the NVRAM, and work your way around the tools in Recovery mode? That said, I have only had one slightly anxious moment here, so Mojave’s betas are looking very good – more robust that El Capitan’s last release on some models of Mac!

One excellent way of testing Mojave’s betas is by making a dual-boot system, with High Sierra installed on the internal storage, and Mojave on an external drive. Given an SSD with a fairly brisk interface to the Mac, this can provide a reasonable level of protection to that Mac. If the worst comes to the worst, you can shut it down, disconnect the external drive, and start up in High Sierra, fingers crossed.

Some users have tried to do this, only to discover that the Mojave beta installer won’t complete its full installation on their external drive. This seems most common with drives connected via USB to a USB-C port on MacBooks and MacBook Pros. You can work around this by connecting the external drive to a USB-C or Thunderbolt hub, or using a drive case with its own USB-C port. If your external drive is currently in a case with a traditional USB port, USB-C cases are quite inexpensive and may improve its performance too.

Many apps compatible with High Sierra also work fine on the Mojave beta. Most of my free tools, listed in Downloads above, are highly or fully compatible, and each week I am porting more. Where many current apps will fail is in their support for Dark Mode: to get the best out of that, they need to be rebuilt using the latest beta release of Xcode, and thoroughly tested on Mojave.

If you’re busy porting your own code on Mojave, I wish you success. Almost all my key support tools – Consolation 3, xattred, Cirrus, and so on – now work properly in both Light and Dark Modes, and look really good on Mojave too. The current release of Consolation 3 has additional support for the unified log in Mojave with many features which are not available in Console, and almost impossible to implement using the log command in Terminal or scripts.

If anyone using Mojave has any problems with any of my apps, or needs additional features or tweaks, you only have to say, either here as a comment or via email.