Are HyperStudio and SuperCard still around? Interesting - but I don't think either of them compete with good ol' HyperCard 2.x.
I quite liked HyperCard 2.3, upgraded to 2.4, it had color, and all of the other cool hypercard things.
As has been said, you can do almost anything in HyperCard - and if you cant do it in HyperCard, it may not have been possible in that time.
I've done simple animations, and a lot of things I would do in Flash today using HyperCard.
There was also a network stack sharing/serving thing, I think it let you server up stacks over HTTP - interesting collab/network-hypercard opportunities with that, especially using text fields.
I've also always wanted to make hypercard stacks talk to eachother over a network. Hypercard-Chat or Hypercard-Forum, anyone? Limited usefulness today, but it would be super-nifty to see.

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