Free as in Freedom: Richard Stallman's Crusade for Free Software
Williams wrote this biography of Richard Stallman with Stallman's cooperation but without his editorial control, and the result is both sympathetic and clear-eyed.
The book traces Stallman's path from the MIT AI Lab's culture of shared code through the founding of the GNU Project and the Free Software Foundation to the creation of the GPL — the license that turned a personal ethic into an institutional mechanism.
Williams is especially good on the tension between Stallman's absolutism and the pragmatic needs of a movement that wanted to win adoption.
The book was published under the GNU Free Documentation License and is freely available on gnu.org, making it a primary document as well as a secondary one.
For product people, understanding Stallman is understanding the ideological bedrock beneath every open-source dependency in your stack.
You do not have to agree with him to recognize that his choices shaped the infrastructure you build on.
Central argument
Williams argues that Richard Stallman's significance lies not in technical invention but in the conversion of a programming ethic — the MIT AI Lab's informal norm of shared code — into durable legal and institutional infrastructure. The GPL is the book's central exhibit: a license engineered to make software freedom self-perpetuating by turning copyright law against itself, compelling any derivative work to remain open. Williams also argues that Stallman's uncompromising absolutism, while personally costly and politically isolating, was strategically essential: it established a hard ideological pole that made every pragmatic compromise in the free software movement legible as a compromise rather than as the natural order.
Critique
Because Williams wrote with Stallman's cooperation, the book's frame remains largely internal to the free software worldview — the antagonists (proprietary vendors, pragmatic open-source advocates like ESR) are rendered somewhat flatly, and the legitimate arguments for proprietary models or permissive licensing receive less genuine engagement than Stallman's positions do. A reader wanting to understand why the BSD or Apache licensing traditions emerged as serious alternatives, rather than merely as concessions to adoption pressure, will need to look elsewhere. The biography also predates the era of platform capitalism, so it cannot reckon with how the GPL's copyleft mechanism proved largely ineffective against the dominant appropriation strategy of the 2000s onward: running free software as a service rather than distributing it.
Why it matters for product
Every non-trivial product stack today includes GPL, LGPL, or AGPL-licensed dependencies, and the legal and strategic constraints those licenses impose — on SaaS architecture decisions, on what can be forked and commercialized, on contributor agreements — are direct consequences of the institutional choices Williams documents. More broadly, Stallman's career is a case study in how a product or platform's governance model encodes values that outlast their author's influence: the GPL is essentially a policy mechanism embedded in a distribution artifact, which is a pattern product leaders replicate whenever they design API terms, data portability rules, or ecosystem incentive structures. Understanding the original intent clarifies why those mechanisms behave the way they do under pressure.