Bush is considered the "grandfather" of hypertext. He proposed a system called the "memex" as long ago as 1945 [Bush, 1945]. Though the system was never implemented, the concepts are still relevant to this day. Bush was concerned about the explosion of scientific literature which made it impossible even for specialists to follow developments in a field. He felt the need for a system that would help people find information more easily than was possible on paper.
The Memex would store information on microfilm which would be kept on the user's desk. The desk would contain many translucent screens on which several microfilms could be projected for convenient reading. The would also be a keyboard and sets of buttons and levers.
The Memex would have a scanner for user input of new material and it would also allow users to make handwritten marginal notes and comments. Apart from the conventional form of indexing, Bush proposed "associative indexing, the basic idea of which is a provision whereby any item may be caused at will to select immediately and automatically another. This is the essential feature of memex. The process of tying two items together is the important thing." [Bush, 1945].