The GNU Manifesto is the founding document of the gnu-project and the political-philosophical statement that launched the free software movement. Published in March 1985 in Dr. Dobb's Journal, it was an expansion of the original "GNU's Not Unix" announcement stallman had circulated via USENET in September 1983. The Manifesto makes both a practical case (GNU will provide a complete Unix-compatible operating system) and an ethical case (software must be free for the good of society).
The document opens with the announcement of the GNU project and an appeal for programmers to contribute time and code. It then pivots to a sustained argument that software sharing is not just tolerable but morally required. stallman frames proprietary software as a social harm: it forces users to accept conditions that divide and impoverish the community of programmers and users alike. The manifesto is explicit that this is not primarily about cost — free as in freedom, not price — but about the right to study, modify, and redistribute.
The Manifesto addresses anticipated objections with unusual directness. Can programmers survive if software is free? Stallman argues yes: through services, custom development, teaching, and support. Won't people take without giving back? Some will, but the harm is less than the harm of secrecy. Is this communism? No — the argument is that intellectual works, unlike physical goods, can be shared without depriving anyone.
The historical context is the dissolution of the mit-ai-lab hacker community, which stallman experienced as a direct loss during the period mit-ai-lab-hacker-culture-1971-1984. When Symbolics hired away most of the AI Lab hackers and began asserting proprietary control over Lisp Machine software that had been developed in a sharing culture, stallman experienced this as a moral injury. The Manifesto is his response — not just a lament but a program of action.
The Manifesto's importance extends beyond its content. It established the free-software-foundation as an institution with a mission, provided the conceptual grounding for copyleft as a legal mechanism, and articulated the four-freedoms in embryonic form (later formalized in free-software-definition-essay). It also drew the line that would later define the software-freedom-vs-open-source debate: free software is an ethical question, not merely a development methodology.
steven-levy's account in hackers-levy provides context for the MIT culture that shaped stallman's thinking. The Manifesto remains required reading for understanding why stallman founded the gnu-project and why the ethical dimension is, for him, irreducible.