After working with UNIX of various flavours for over ten years, I needed to learn AIX in a hurry. This is a thorough book, with plenty of examples and careful, detailed explanations. There is a good introduction to RS/6000 and pSeries hardware, and then the reader is pushed into the operating system at the deep end. You will need a good grounding in UNIX to get through this book -- it's not a beginner's introduction. My only gripe is that the index is rather sparse -- you need to be very patient if you don't know exactly what you're looking for. But for the right audience, this book is a real treasure.