Brewster Kahle · Public domain

A computer scientist whose 1962 doctoral thesis applied queueing theory to message-switching networks, laying the mathematical groundwork for how data moves across the internet before the internet existed. He went on to play an influential role in building the ARPANET in the late 1960s, and his theoretical work on hierarchical routing with student Farouk Kamoun in the 1970s remains part of how the internet's traffic is organized today.