Hypercard stacks were the equivalent of websites.
If it had been built around the Macintosh Toolkit, and had an API that fit in with Mac apps, there wouldn't be a web, we'd all be using Macs. Alas it was all on its own, didn't work with Mac apps. Missed opportunity.
A lot was lost because the Mac development model was far in advance of what existed on the web, and it was well-thought-out unlike the app model of the web, which is a hodgepodge of horribly designed modules that don't work well together.
I was a Mac developer at the time, so I know a lot about this moment of history.
Screen shot of a Hypercard stack home page.