[xorbyte]

Not sure how you see progress and innovation otherwise. Much of what is good in Linux comes from experimentation and people/distros 'doing their own thing' which sometime improved the ecosystem, and sometimes resulted in abandoned projects. But things have not stagnated.

As for UNIX, perhaps you're familiar with Plan 9? Some of the principal UNIX designers were unhappy with the result, so they went and worked on improving it. Nothing is good enough the first time around.

[pjmlp]

I lived through the UNIX wars, where POSIX doesn't mean a thing because each UNIX has its own version of standard and most complex applications still required OS specific APIs anyway.