[Someone]

If you think through, it is not _that_ obvious; it can't be turtles all the way down. So, where did the first binary software come from?

The answer is that somebody punched in a program from a computer's console, probably somewhere in the early 1960s, but possibly earlier. That program was used to make it easier to enter other programs, etc.

Given that copying working code is so simple, chances are that most of the currently running hardware can be traced back to a few persons entering a boot loader by hand.

That might even be one person. For example, Windows NT was initially developed for Intel's i860 (http://en.wikipedia.org/wiki/Windows_NT#Development), so chances are that it was bootstrapped from a Unix machine. Because of that, it may trace back to the same initial boot loader as, for example, Mac OS X.

[PeterisP]

Well, to be detailed, both the first kernel and the first compiler was probably entered from a stack of punchcards or punch tape made with mechanical "typewriters"; punching a program from console is rather unwieldy and generally you should do that only for the bootloader that loads the rest of the (manually compiled) code from some electromechanical device.