This past week, Microsoft acquired open-source code repository GitHub. In the longue durée of the tech industry, it was a world-historical about-face: open-source code, which allows other programmers and interested parties to view, and even copy and modify code, arose in opposition to software companies that rely on strong intellectual property protections to wall off their products from technologically skilled users.

In its early days, personal computing was a hobbyist pursuit in which young men (and it was mostly men) tinkered collectively with mail-order kits. Commercial software was scarce: you had to program things yourself. Within this milieu arose a robust culture of cracking things open and sharing what insights you found. Learning from others’ code was commonplace, as was passing around programs.

As we know now, one person’s “sharing” is a property owner’s piracy. Instead of buying programs, hackers were copying them and making their own. In 1976, a young Bill Gates, trying to get his software company off the ground, sent a now-infamous letter to the Homebrew Computing Club newsletter that drew a line in the sand. “As the majority of hobbyists must be aware, most of you steal your software. Hardware must be paid for, but software is something to share. Who cares if the people who worked on it get paid?” Beyond snatching dollars out of the pockets of the soon-to-be richest man in the world, piracy created a problem for software itself. “One thing you do is prevent good software from being written,” Gates wrote, before helpfully offering a mailing address to which software pirates could send their belated payments.