[TKZ227]

I have heard of different kinds of commands processors like "dcmd" and "zcmd", but I'm not sure exactly what they are, and which one I should use/learn. I have only ever used strcmp before (I think that's what it's called), and I can script just about any commands with it. However, I have heard that people are moving to new command processors because they are more effecient and less time consuming to create. Which one should I use? Do you know any tutorials on them?