Prototrak is extremely wide spread, it might be harder to find a shop without some form of their machines these days.
As for transferring conversational programming knowledge between different machines tools.... Somewhat. You will need familiarity with all the preparatory code like g40,g80,g17..etc . But a lot of machines these days come with a form of conversational programming... FAPT, shopmill/shopTurn, mazatrol, visual quick.
Once you figure out what the machine tools are expecting, then a lot of the code and it's placement becomes second nature.