And .ain which was even better but now seems to be half lost to time (no Wikipedia, just a few links repeating the same fragments of info like http://justsolve.archiveteam.org/wiki/AIN)

PWAs could have been so good. redbean/llamafile might be the closest, though.

I mused about the idea of a version of Hypercard where you could load cards from network resources, or even just stacks. Ultimately though it would have been an even bigger security nightmare than the original Javascript. Hypercard was developed long before security was even a consideration on consumer hardware. The only thing it had was 5 different access levels, from a view only mode to full developer support.

It's as much of a fantasy as the one where Apple released a version of Hypercard for Windows 3.1 and blew Qbasic out of the water. It's a real shame Apple just chucked one of the most interesting beginner programming environments in the trash just as so many new people were getting interested in programming.