To my knowledge, RoboHelp may be installed on any number of computers. What counts, is how many "Activations" you may have at any given moment. And I believe that number is TWO. So theoretically, you could install it on all three machines, but only activate it on two of them. If you needed to use it on a third, you would then deactivate it on one of the machines and RE-activate it on another.
But here's the kicker. You are limited to the number of times you can de-activate and re-activate before you are then forced to call Adobe and work through the process a different way.
I stand to be corrected here, but if you needed it active on three machines, you need two separate licenses.
Thanks Rick. But I have just one thing to say: Argh....
In this world of mobile work forces, it wouldn't seen unlikely that an individual developer would be working from the office, from home, and from the road.
I'm certainly hoping Adobe (an employer of many programmers who probably operate the same way) is sensitive to that in their EULA.