Revolution OS is a documentary that is about the history of GNU, Linux and open source and free software movements. It includes numerous interviews with prominent hackers and entrepreneurs, including Richard Stellman, Michael Tieman, Linus Torvalds, Larry Augustine, Eric S. Raymond, Bruce Perrance, Frank Hecker and Brian Behldorff.
There is also a mention of that open letter from Gates in which he asks computer hobbyists not to share software but to buy.
In this film Richard Steallman described how and why he left MIT Lab for Artificial Intelligence to dedicate his life to the development of free software, as well as how he started with the GNU project. Linus Torvalds has been interviewed on the development of his Linux kernel as well as the GNU / Linux naming controversy and further development of Linux, including its commercialization. Richard Stallman comments on some conceptual aspects of open source, including communism and capitalism as well as many aspects of the development of GNU / Linux.
You can watch the Revolution OS movie online here.