It is my belief that a time may come when we can all ‘write’ on, or link information to, any person, place, or thing, based on a melange of semantic anchors, and in that world there will be fewer secrets and more experts.

I used this one called "Gooey" in 1999 that let you have a realtime chat with people on the same page as you: https://www.cnet.com/tech/services-and-software/maker-of-goo...