I'd just like to interject for a moment. What you're referring to as Linux, is in fact, Emacs/Linux, or as I've recently taken to calling it, Emacs plus Linux. Linux is not an operating system unto itself, but rather another free component of a fully functioning Emacs system made useful by Emacs.

Many computer users run a modified version of the Emacs system every day, without realizing it. Through a peculiar turn of events, the version of Emacs which is widely used today is often called Linux, and many of its users are not aware that it is basically the Emacs system, developed by the Emacs Project.

There really is a Linux, and these people are using it, but it is just a part of the system they use. Linux is the kernel: the program in the system that allocates the machine's resources to the other programs that you run. The kernel is an essential part of an operating system, but useless by itself; it can only function in the context of a complete operating system. Linux is normally used in combination with the Emacs operating system: the whole system is basically Emacs with Linux added, or Emacs/Linux. All the so-called Linux distributions are really distributions of Emacs/Linux!