"There is no clear way to blend two standard websites together, but it’s obvious how to blend two streams. You simply shuffle them together like two decks of cards, maintaining time-order — putting the earlier document first. Blending is important because we must be able to add and subtract in the Cybersphere. We add streams together by blending them. Because it’s easy to blend any group of streams, it’s easy to integrate stream-structured sites so we can treat the group as a unit, not as many separate points of activity; and integration is important to solving the information overload problem. We subtract streams by searching or focusing. Searching a stream for “snow” means that I subtract every stream-element that doesn’t deal with snow. Subtracting the “not snow” stream from the mainstream yields a “snow” stream. Blending streams and searching them are the addition and subtraction of the new Cybersphere."
— TIME TO START TAKING THE INTERNET SERIOUSLY- David Gelernter
