Pour your coffee, sit down, and log in: It’s the routine of hundreds of millions of knowledge workers.
As businesses add a crazy quilt of online services to the tools we use, those logins keep piling up. Information-technology managers—when they don’t just throw up their hands—have long dreamed of a nirvana called single-sign-on, where one login rules all. And increasingly, those login credentials will live up in the cloud, managed by some Web giant.
Three companies are on a collision course, jostling for control of the keys to our professional identity. They are Google, Microsoft, and LinkedIn.