In 2001, then-Microsoft CEO Steve Balmer complained that “Linux is a cancer.” The future Los Angeles Clippers owner was referring to how Linux’s open source license — The General Public License — necessitate all the software it is built on be transformed into open source as well. His fears were overblown, but also prescient in a way he probably didn’t realize. Twenty years on, it is Linux — not Windows — is the most widely used operating system on Microsoft Azure. But it was customer demand, rat...