F5 Networks named itself after the strongest class of tornado, and it sold shelter from a storm of web traffic. In 1999 the busiest websites were learning that one server was never enough. Visitors arrived in surges, and a single overloaded machine could take a whole site down. F5 sold a box that sat in front of a group of servers. It sent each visitor to the server best able to respond. F5 went public that June.

BIG-IP in Seattle

Michael Almquist and Jeff Hussey founded F5 in Seattle in 1996. The bet was that websites would become critical services that could never fail. Their product, BIG-IP, checked the health of each server and routed traffic around failures. It turned a rack of ordinary machines into one reliable website. Online retailers, portals, and banks were among the early customers. They needed their sites up at every hour of the day.

Its Customers Vanished, F5 Stayed

F5 priced its offering at $10 a share in June 1999. The stock climbed through the boom. In 2000 and 2001 it fell sharply, as many of its dot-com customers disappeared. F5 rebuilt around large enterprises and service providers. It added security and application delivery features. F5 became one of the long-term survivors of its class, and it remains a public company today, trading on the Nasdaq as FFIV.

Cover: Storm, Anders Zorn. Art Institute of Chicago, public domain. Chosen for a storm (the F5 tornado).