Tim Berners-Lee
Tim Berners-Lee is the computer scientist most closely associated with the creation of the World Wide Web. In this wiki he matters as the figure who brought together the browser, server, URL structure, HTML, and HTTP into one working web system at CERN in 1990.
That combination matters more than any single invention in isolation. The web became usable not because one protocol existed, but because naming, linking, retrieval, and display were made to work together under open standards.