"Free as in Freedom" (2002) by sam-williams is the first full-length biography of stallman and the primary narrative source on his life, character, and the development of his ideas. It was published by O'Reilly Media — a detail not without irony, given tim-oreilly's role in promoting the "open source" framing that Stallman opposes.
The book covers Stallman's childhood and early mathematical aptitude, his years as a programmer at the mit-ai-lab during the mit-ai-lab-hacker-culture-1971-1984 era, the events that motivated the announcement-of-gnu-project, the founding-of-fsf, and the development of gpl-v1 and gpl-v2.
Williams conducted extensive interviews with Stallman and many of his associates, producing a portrait that is sympathetic but unsparing about Stallman's personal difficulties and inflexibility. The book captures the hacker-ethic-mit environment documented in hackers-levy and traces how Stallman transformed that ethic into a formal free-software-definition and legal instrument in the gpl-copyleft-mechanism.
The book was subsequently released under a free license, and stallman produced a revised edition — free-as-in-freedom-revised — in which he corrected factual errors and added his own perspective on events Williams had described. The two versions together offer both an outsider's view and Stallman's self-account.
Essential reading for understanding the founding-gnu-and-fsf-1983-1991 era and the personal motivations behind the four-freedoms philosophy. Should be read alongside hackers-levy for the full cultural context.