What is the incentive to provide a free operating system? Why do all this work for no pay? Why not sell it?
closed as not a real question by Gilles, Call me V, nitstorm, Uri Herrera, Jorge Castro Jul 5 '12 at 13:37
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You are confusing "free" with "zero dollar". Linux is free as in free speech. This doesn't not prohibit anyone from selling or profiting from it, and many people do just that.
This seems to be a two part question so i will try to answer piece by piece.
** The idea is for free and open source software for that matter works since the sum becomes more than the pieces themselves**
this works so well not only because it is free. But also because it is open source.
Many people / companies have different needs they have to satisfy.
Lets say one company likes a particular feature in Linux, and decides to use it in a commercial product. Maybe they realize they can make it even better, earning them more profit by delivering a better product to their customers. Since they are using an open source product they are bound by the GPL license to open source any modifications they have made. Also releasing their modifications back could mean that the changes are accepted into the main kernel development, guaranteeing that the changes they made will automatically be included in new version of the kernel. It is simply being selfish behavior. By helping themselves they also happen to help others.
Some things are good some things are bad. The Kernel itself known to be of very high quality regarding stability and quality of code. This does not mean that all software or drivers for hardware is equally good. This can of course affects the overall experience of using Linux. But Amazon use Linux in their cloud environment and on their e-readers. Google has been able to become one of the biggest companies in the world using Linux as the OS of choice for its services. And I believe looking at their choice argues that it's of pretty high quality since they are using it to serve millions of customers.
Short answer: That way lies madness.
Longer answer: Originally, operating systems were built for each computer individually. Being so specific there was no opportunity to market those OSs to other people for other machines. Later with the advent of UNIX, there was opportunity for a certain standardization. Computing was a very collaborative process. Yes, there were rivalries and egos and races to the finish, but the goals were to make the best programs no money could buy.
Then came the day when someone thought that since he was expending effort at rewriting a program, he was deserving of payment for his efforts. And he convinced others that there was monetary value to his work. Others took up this belief structure and now we have a whole industry founded on that idea.
Yet the process of creating for its own sake in the computer world continued with UNIX and other OSs and now it carries on with some guy's master's thesis.
The process of creating can be its own reward. To be able to have an international community look at, use and examine what you've created is a wonderful feeling. It also travels at your own pace. There is no supervisor writing performance reviews about your lack of promptness on your delivery. You do what you can with what you have and deliver it unto that community. You hope it is received well, you hope it gets used and hopefully you continue to believe in it.
Linux and Ubuntu are very different from the charged-for software business models. They much more foster a sense of community. They offer a sense of belonging and a sense of accomplishment that folks may not find in other more financially based systems. Everyone may participate up to their own level of ability. And they may see that level grow with their continued participation.
If someone has a desire to be paid for their software related efforts, then let them go work in the software for sale industry. For the time being, it has its place in the world. But to be a part of computing history, rather than part of a business model, then the answer is to participate in fora like these and make the tiniest bit of difference in how mankind relates to their world.