HTML and CSS Reference
it. However, this is no substitute for understanding how HTML and CSS really work, and some WYSIWYG
editors can generate convoluted, presentational markup. Handcrafting your documents in plain text is
really the best way to maintain control over every aspect of your markup, and many professionals swear
Choosing a Web Browser
As we mentioned earlier, a web browser is the software you use to view websites, and you almost certainly
have one already. Every modern computer operating system comes with some sort of web browser
installed, or you can choose one of the many others on the market:
Microsoft Internet Explorer is the default browser on Windows operating systems.
Apple Safari is the default browser for Mac OS X, and is also available for Windows.
Mozilla Firefox is a free browser available for Windows, Mac OS X, and Linux
( mozilla.org/firefox ).
Opera is another free browser available for a wide range of operating systems ( opera.com ).
Google Chrome is a free browser for Windows, Mac OS X, and Linux ( google.com/chrome ).
Konqueror is a free browser and file manager for Linux ( konqueror.org ).
Ordinary HTML documents don't require any other software to operate. All of your files can be stored
locally on your computer's hard drive, and you can view pages in their rendered state by simply launching
your browser of choice and opening the document you want to view (you can find the command to open a
local file under the File menu in most browsers).
Validating Your Documents
Having a standardized set of rules is all well and good, but how can you be sure you've followed them
correctly, crossing all the t s and dotting all the i s? You should validate your HTML documents, checking
them against the standard rule set to ensure that they're put together properly. It's like a spell-checker for
markup. The W3C has created an online validation tool (available at http://validator.w3.org/ , sh own in
Figure 1-2) for just this purpose. This web-based service allows you to validate your documents by either
entering the location of a page on the Web, uploading a file from your computer, or simply pasting your
markup directly into a form on the website.