To create the XML documents we'll use in this book, all you need is a text editor of some kind, such as vi, emacs, pico, Macintosh's BBEdit or SimpleText, or Windows Notepad or Windows WordPad. By default, XML documents are supposed to be written in Unicode, although in practice you can write them in ASCII—and nearly all of them are written that way so far. Just make sure that when you write an XML document, you save it in your editor's plain text format.
Using Windows Text Editors
Windows text editors such as WordPad have an annoying habit of appending the extension .txt to a filename if they don't understand the extension you've given the file. That's not a problem with .xml files because WordPad understands the extension .xml. ...