I find that the most robust AppleScript mode for Emacs is that apples-mode. The problem is that the package is a mystery. I’ve investigated a bit because I wanted to ask for a few modifications and get some trivial PRs accepted but there is no trace at all of the author.
I’ve checked the email, the account name, etc. and I don’t get anything. It looks like somebody wanted to not be identified, put the code online, added a few fixes and just left the thing there.
It’s weird because the code is of very high quality. It indicates that the person was familiar with Emacs coding and packaging, and familiar with AppleScript too. I thought it could have been an Apple developer who put his own work code there but anonymously and then left Apple and had no use for the code anymore.
I don’t suppose there are lots of people in the Applescript community who are familiar with Emacs, but I’d love to see a fork of the code with updates so that the package can be used to work on the latest versions of macOS.