I have seen some gloomy posts here, but I think its not all that bad.
As best I understand:
- An application will still run even if the Apple Developer ID has expired
- An application can be installed if the Developers Apple Package ID is still valid
I note that Mark is still publishing the odd applications here and there and the down load page is still up. I think that means he is maintaining his Apple Package ID.
Now, about where to install.
When I started using Macs in 2005, I used Parallels to quite seamlessly run Windows at same time as OSX. OSX was the host OS, and Windows was the guest OS run on a virtual machine. The Windows desktop appeared as a window on the OSX desktop. I used this to run a few Windows applications that were not available for OSX, or had less functionality in OSX. Eventually I got rid of the Windows box entirely, and had 3 different Windows versions as guest OSs.
A bit later, OSX went from 16 bit to 32 bit, and I used Parallels to run an older version of OSX as guest so that I could run a few 16 bit applications. I also had a versions of Linux of Android.
Parallels is being actively maintained, developed and sold in 2026 for Macs with M series chips; only Arm versions of operating systems are supported. Guest OSs include Windows 11 Pro, MacOS 13,14,15 and 26, and six Linux distros.
I gave up Parallels when I moved to Apple Silicon as I didn’t see any point in having Windows 11, but now supporting a legacy MacOS version becomes useful with the end of Rosetta.
I plan to set up Sequoia as a guest OS before I upgrade to Tahoe. There are a few Intel Applications that I want to keep, and I will try Script Debugger on it as well.
Parallels used to be quite agile at sharing folders between guest and host OSs so I may well be able to use the same Script Library folder between guest and host.