For the purposes of completing the exercises in this book, you will need a text editor. Most PCs will come with one—usually Notepad on Microsoft Windows, or TextEdit on Mac OS X. There are literally thousands available for free or low cost, with varying degrees of features.
If you are an existing developer, you will likely have your editor of choice already; for those of you who are new to editing, it is a matter of trying a few, and seeing which you prefer. There are some features I would recommend you enable or use: