NEC marketed a dataflow MPU back in the 80's. I
believe it was
targeted at the DSP market. To my knowledge, it's the only
commercial dataflow design.
Multiflow Trace series, as well.
The good ol' AS/400s (with yesterday's S/38 and today's iSeries) are
probably the weirdest machines in the last twenty years that actually
made a mark in history.
--
Will