This book is for anyone who wants to learn XPath and how it's used today. We'll assume you've had experience with XML and HTML, but that's all we'll assume. We will be using the (free and downloadable) Java language when we discuss XPath 2.0 in order to run the (also free and downloadable) Saxon processor (the only one that handles XPath 2.0 at this point), but you'll get all the details on how to get that working.
We're going to be as platform-independent as we can be in this book. XPath is not the province of any one particular operating system, so we're not going to lean one way or the other on that issue. On the other hand, it's a fact of life that a great deal of XML-oriented software these days is targeted at Windows. And among the standard browsers, the Internet Explorer has many times more XPath 1.0 support than any other browser does. This book doesn't have any special pro- or anti-Microsoft bias, but to cover what's available for XPath these days, we're going to find ourselves in Microsoft territory sometimes; there's no getting around it.