The movie entitled Revolution OS talks about how operating system evolves. It also tells the inside story of the hackers who rebelled against the proprietary software model and Microsoft to create GNU/Linux and the Open Source movement. The documentary film interviews with Linus Torvalds, Richard Stallman, Bruce Perens, Eric Raymond, Brian Behlendorf, Michael Tiemann, Larry Augustin, Frank Hecker, and Rob Malda. Those are the people who actually participated in the history that they are discussing. It discusses how change came in 1978 as Bill Gates, in his Open Letter to Hobbyists, pointedly prodded hobbyists to pay up. It also describes the development of the Linux kernel, the GNU/Linux naming controversy, Linux's further evolution and its commercialization. Revolution OS tracks down the key movers and shakers behind Linux, and finds out how and why Linux became such a potent threat.
I think that revolution os gives me an idea about the history of the operating system. This is only the time that I know that when computers were new, software was traded freely between users without much thought to ownership and intellectual-property rights. This lax attitude (which extended to software developers) allowed users to liberally modify the underlying language (aka source code) of computer programs to make them more useful for certain applications. It seems that only Bill Gates led the way in the notion of "proprietary software" — but keeps the source code firmly under lock and key, which makes it pretty much impossible for anyone else to adapt the code to suit his or her needs. Only Bill Gates get the best idea make much money on operating system.