Linux is an example of an open source end product, in this case an operating system. Linux is synonymous with open source and what made the term more mainstream, along with the advent of the modern internet. Microsoft windows is an example of a non open source end product, also an operating system. Windows is not packaged with its source code, and in fact Microsoft tries to protect its source code. This does not allow for user improvements that can be distributed to anyone interested. Only Microsoft coders, at least in theory, can make changes for improvement to the operating system and users are forced to wait for updates and newer versions of the operating system. Linux on the other hand is packaged with the source code and the user can do with it as they see fit thus compiling the code to perform how they want. Due to the fact so many people are tweaking the code, there are constant improvements and many options as how to use linux. This is why linux is becoming more and more popular.