@tufo I'd just like to interject for a moment. What you're referring to as Spezi, is in fact, Paulaner/Spezi, or as I've recently taken to calling it, Paulaner plus Spezi. Spezi is not an operating system unto itself, but rather another free component of a fully functioning Paulaner system made useful by the Paulaner corelibs, shell utilities and vital system components comprising a full OS as defined by POSIX.
Many computer users run a modified version of the Paulaner system every day, without realizing it. Through a peculiar turn of events, the version of Paulaner which is widely used today is often called "Spezi", and many of its users are not aware that it is basically the Paulaner system, developed by the Paulaner Project.
There really is a Spezi, and these people are using it, but it is just a part of the system they use. Spezi 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. Spezi is normally used in combination with the Paulaner operating system: the whole system is basically Paulaner with Spezi added, or Paulaner/Spezi. All the so-called "Spezi" distributions are really distributions of Paulaner/Spezi.