What better way to learn programming than to have the source code to all of the sofware you use every day available to you?
OpenSource operating system like LinuxOs or another UnixOs gives you just this. There is a lot of OpenSource philosophy explaining why it encourages more people to make better software, but you can just take our word for it that OpenSource systems are much easier for programmers to support. It’s not possible for vendors to hide the details of using their systems when the source code to them is available.