> Thinking some more, my guess would be that it was intended to be used
> instead of &end, so that toolchain or system utilities could sbrk() behind
> the scenes without destroying the usefulness of &end, and perhaps for use
> by the infamous historical program or two that did their memory allocation
> by [s]brk(2)'ing until they stopped segfaulting.

Random gratuitous note: I suspect that rolling your own cycle-based
memory manager involving periodic brk(&end) calls was more common in
the early days.

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