Apple looks to be furthering gatekeeper protection with additional checks on distributed binaries, we can see some details about it here: https://developer.apple.com/developer-id/ and a little more from Ars here: https://arstechnica.com/features/2018/09/macos-10-14-mojave-the-ars-technica-review/10/#h3
It seems Apple wants to perform some kind of basic review of signed binaries and to then act as a notary on the developer’s signature, vouching for it not containing malware etc, so they can be less dramatic when warning people about the dangers of using programs they’ve downloaded. It’s optional at the moment, but Apple says: “in an upcoming release of macOS, Gatekeeper will require Developer ID signed software to be notarized by Apple.”
Feels a bit like typical Apple nannying/over-reach, but I can see the benefit to consumers and the platform as a whole, so I’ll just go along with this without too much resistance.
I’m wondering if anybody has any experience of this with audio plug-ins, maybe somebody has tried it if they knew about it a while ago, and/or knows what the future implications for audio plug-ins is likely to be when it becomes mandatory.