Williams begins with the famous jamming printer and Stallman's encounter with a non-disclosure agreement that prevented him writing reporting software for it. He then jumps forwards to a speech given by Stallman in 2001, responding to attacks by Microsoft on the GNU GPL. Having used these episodes to introduce Stallman and explain the basic idea of free software, the rest of the work continues in a similar vein, mixing historical chapters with ones describing Williams' own meetings with Stallman.
Chapter three describes Stallman's childhood as a prodigy; chapter four his experiences at Harvard and MIT; chapter six the MIT AI Lab and the Emacs "commune"; chapter seven the death of the MIT hacker community and the first announcement of the GNU Project; chapter nine the GNU GPL; chapter ten the appearance of Linux and debates over GNU/Linux; and chapter eleven the coining of the term "open source" and the arguments over that. These contain quotes by everyone from Stallman's mother to the leading lights of free software, as well as plenty by Stallman himself. The narrative never strays too far from its subject, but becomes inextricably interwoven with the broader history and politics of free software and sometimes digresses to cover key figures and events with which Stallman wasn't directly involved.
Williams' first-hand accounts help give Stallman a human face: chapter five recounts a meeting in 1999 LinuxWorld, chapter eight a meeting in Hawaii, and chapter twelve a frustrating car trip with Stallman at the wheel. These give a feel for Stallman's personality and presence, his forthrightness and emotional intensity, his steadfastness and his abrasiveness, and his ability to unsettle. Chapter thirteen attempts to predict Stallman's status "in 100 years", quoting opinions from Eben Moglen, John Gilmore, Eric Raymond, and Lawrence Lessig; it also suggests that Stallman's personality may be inseparable from his achievements.
Although I had already been involved with free software advocacy for some time, my first encounter with Richard Stallman came when he turned up to a rehearsal of my gamelan group; afterwards I tried without much success to explain to my fellow musicians why the strange bearded man they'd just met was so important. I don't think Free as in Freedom would help much with that: it jumps around too much and assumes too much general knowledge of the computer industry to be a good introduction for complete outsiders. Those already interested in the history and politics of free software and hacker culture, however, should relish it.
In an epilogue Williams talks about the writing of Free as in Freedom and the choice of copyright licence: the entire book is available online, under the GNU Free Documentation License, along with errata and other information.