In the 1980s, I had the chance to spend several years arguing about free and open software, what we now call open source, with the founder of the movement, Richard Stallman. My office at the MIT AI Lab was next door to his. Stallman’s position was that the source code to software should be free for everyone to use, learn from, and improve. Software encapsulates knowledge, he argued, and no one should lock something so fundamental away. To hide software inside a company was to hide knowledge itself.
At first I took the conventional view of the time. Software would only advance, I insisted, if companies kept proprietary control over their code. We agreed on the bigger picture—that computers would become a central accelerator of human progress—but disagreed sharply on how to get there. What I missed was that software was not just a commercial asset; it was a body of knowledge, and bodies of knowledge grow stronger when they are shared. After about two years of on-and-off debate, Stallman convinced me I was wrong.
Over the following years, Stallman turned that conviction into a movement. He argued that people should be able to study the software they used, change it, improve it, and share it with others. That became the free software movement, and it later helped form the foundation for what the world now calls open source.
