ServiceNow began as a cloud help desk for IT tickets and grew into one of the largest software makers in the world. When something broke, an employee filed a ticket in its software, and IT staff tracked the fix. The company sold this as a subscription on a platform customers could extend. When ServiceNow filed to go public in 2012, large companies were starting to trust cloud software with core work. Frank Slootman was chief executive.

Glidesoft in San Diego

Fred Luddy founded the company in San Diego in 2004 as Glidesoft. He had been chief technology officer at Peregrine Systems, a maker of IT management software. He wanted a platform that made it easy to build business workflows. His bet was that IT service management made a good first use, and that the same platform could later handle much more of a company's work.

Far Beyond IT

ServiceNow priced at $18 a share in June 2012 and rose on its first day. It grew far beyond IT, into human resources, customer service and security work. Its value climbed into the hundreds of billions of dollars. Later chief executive Bill McDermott pushed it further into AI. ServiceNow remains a public company and one of the largest software makers in the world.

Cover: The Clock Tower, Venice, Donald Shaw MacLaughlan. Art Institute of Chicago, public domain. Chosen for a clock tower (now).