NoteCards was done at XeroxParc in the 1980s. It featured typed objects and links. Each piece of hypertext (a "card") was placed in a separate window on the screen.
NoteCards inspired Fuji Xerox to create ViewCards? for the Viewpoint office automation system. Similar to some uses of NoteCards, the model was that you were using a box of index cards and linking them together to organize the outline of an article, thesis, etc.
Another system was "MailCards?" which was a hypertext mail system.
Wow! It is real! Venue took over and supported Xerox Interlisp-D. It also appears that they have packages such as NoteCards and Loops, as well. Wow. It lives
See also HyperTextHistory