Open source software — software freely shared with the world at large—is an old idea. A guy named Richard Stallman started preaching the gospel in the early ’80s, though he called it free software. Linus Torvalds started work on Linux, the enormously successful open source operating system, in 1991, and today, it drives our daily lives—literally. The Android operating system that runs so many Google phones is based on Linux. When you open a phone app like Twitter or Facebook and pull down all those tweets and status updates, you’re tapping into massive computer data centers filled with hundreds of Linux machines. Linux is the foundation of the Internet.