Sometimes I wish GNU really weren't Unix, more so than it isn't currently. Specifically, I wonder what the alternate reality would be where GNU was a lisp machine instead. After all, lisp machines could run a variety of languages, RMS had experience developing them, and Emacs is practically a mini lisp machine fit to run under other operating systems anyway.

I remember reading rms saying he regretted the operating systems he worked on becoming obsolete when their systems were deprecated. At the time, lisps weren't portable (though, they would become more so in the future), and so IIRC he said he heard that Unix was portable, had not run Unix yet, but thought it looked like a reasonable enough design.

So, as a distraction while hacking on soci.el tonight, I was reading through the first GNU bulletin, and here's a relevant excerpt:

         Why a Unix-Like System?
It is necessary to be compatible with some widely used system to give our system an immediate base of trained users who could switch to it easily and an immediate base of application software that can run on it. (Eventually we will provide free replacements for proprietary application software as well, but that is some years in the future.)

We chose Unix because it is a fairly clean design which is already known to be portable, yet whose popularity is still rising. The disadvantages of Unix seem to be things we can fix without removing what is good in Unix.

Why not imitate MSDOS or CPM? They are more widely used, true, but they are also very weak systems, designed for tiny machines. Unix is much more powerful and interesting. When a system takes years to implement, it is important to write it for the machines that will become available in the future; not to let it be limited by the capabilities of the machines that are in widest use at the moment but will be obsolete when the new system is finished.

Why not aim for a new, more advanced system, such as a Lisp Machine? Mainly because that is still more of a research effort; there is a sizeable chance that the wrong choices will be made and the system will turn out not very good. In addition, such systems are often tied to special hardware. Being tied to one manufacturer's machine would make it hard to remain independent of that manufacturer and get broad community support.