"It looks like you've got clients forking more clients, and that goes out of control fast."

I laughed out loud quite loudly in my office as soon as I read this for some reason. Nice :)

Now if I could get all my clients to fork each other, the problem would take care of itself aye? Haha
~~~~~~~~~ I'm unique, just like everybody else! ~~~~~~~~~

Yes, I would definitely not want a fork bomb.

The process that runs for each client is actually a 3000 line script that uses .NET to automate Internet Explorer in "private" mode, (so they can all run together without cookie_jar issues) So there's no room for more processes than needed.

As said previously I've been just checking the count and sleeping for roughly an hour to let all 10 finish, then starting the next group, but I often see only 1 or 2 left running and realized I could significantly speed it up by ensuring there were ALWAYS 10 running..

I'll incorporate all you guys advice and post the results to show solution.

Oh yeah, I obviously don't want to start my process with system() anymore because that creates another fork right?

Could I just use backticks to call the other script and pass the client ID as $ARGV[0]?

"exec" it