In 1980, at the MIT Artificial Intelligence Lab, a printer jammed.

This was not unusual. Printers jam. What was unusual was the man it annoyed, and what he decided to do about it.

Richard Stallman was a programmer in the lab, and the lab had recently been given a new laser printer by Xerox. A good machine. Fast. It also had a habit the old one shared: it jammed quietly, on a different floor, and left people waiting on pages that would never arrive. The old printer had the same flaw, but Stallman had fixed the social half of the problem. He had the source code, so he rewrote it. He made the machine send a message when it jammed, and tell you when your job was done. A small thing. A neighbourly thing.