POE "Pipeline"

I was wondering if anyone had created the "analog of the Unix Pipeline" for
POE.

This would let someone compose stages whose inputs were essentially lists of
objects to be processed.  The "Pipeline Controller" would handle all the
heavy
lifting (e.g. flow control, signals such as "closing", "fatal" stages).

The stages wouldn't be processes, but event driven things, like most POE
things.

There's a fair amount of cleverness required.  Also some interesting things
that could be done with persistance (e.g. objects between stages for
"lossless"
processing), pipeline construction, and management.

Thanks,

Zero