While it's natural for those with a software orientation to analyze "process control"
as a label for what [open] and [exec], for example, do (they control processes), it's most common in the larger
world to gloss the term as the 
"engineering discipline that deals with ... mechanisms ... for controlling ... a specific
[[physical]] process."
[http://en.wikipedia.org/wiki/Process_control].
[Tcl'ers] with interest and experience in process control include:  [Steve Offutt]; 
[KBK]; [Gerald Lester]; [CL]; [Philip Quaife]; [De Clarke]; [Steve Redler IV]; [AJB]; ...


















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Also see this
[http://www.engcorp.com/acf/process%20control]
entry to a Wiki
focussed on process control with dynamic software.