One of the ironies of history is that war often lifts innovation to a higher level, and many beneficial inventions have roots in warfare. During World War Two, scientists and engineers on both sides of the battle lines advanced technology at a tremendous rate. In particular, the development of radar during and after the war was a catalyst for some of the technologies later incorporated into the Internet. One of the pioneers in radar, Vennevar Bush, was also the originator of an idea that would later evolve into the World Wide Web.

When the U.S. officially entered the war, Bush served as the top advisor to President Roosevelt on matters of technology in the war. He managed all the government's scientists, including the Manhattan Project. Even with this great responsibility, he also found time to keep up on his own research, including a machine intended to change the way people store and retrieve books, records, and notes. He called this machine a memex, because its purpose was to augment human memory.

Bush theorized that people didn't think well in the linear structures of alphabetic or numeric indexes, but instead in associative connections. Therefore, the memex would index everything with associative links and pieces of information that could be retrieved through paths of logical connections. He described the memex as a desk and camera that could record anything a user wrote and then link it to other pieces of information indexed in its storage space.

No memex machine was ever built, but Bush described his idea in an article for Atlantic Monthly titled "As We Think", published near the end of the war in 1945. It was obviously a revolutionary idea, but few people could grasp its potential impact. In the Philippines, a young Navy Radar Technician named Doug Engelbart picked up a copy of Atlantic Monthly at the Red Cross and became an early advocate for Bush's idea.