HTML and CSS Reference
available extensions (such as Firebug, covered more in Chapter 14) that are handy in debug-
ging your web work. For these reasons, we highly recommended that you use Firefox as your
main development browser.
At the time of this writing, Firefox's market share is estimated to be about 12 percent of all
Like all browsers, Firefox has a “rendering engine” as one of its components. This is the
more). Firefox's rendering engine, called Gecko, is available separately with an open source
license so that enterprising folks can build other browsers on top of it. Some other Gecko-based
browsers include Netscape (versions 6 and higher; previously released for several operating
systems but no longer available), Camino (Mac OS X only; see www.caminobrowser.org ), Flock
(Windows, Mac, and Linux; see http://flock.com ) Mozilla Application Suite (available for
several operating systems; see www.mozilla.org ), and Minimo (for small devices such as cell
phones and PDAs; see www.mozilla.org/projects/minimo/ ). Generally speaking, you can
count on all Gecko-based browsers to render your (X)HTML and CSS the same. Thus, it is
probably unnecessary (although it never hurts!) to test your sites in all of these alternative
Another popular web browser for designers and developers is Safari ( www.apple.com/macosx/
features/safari ), Apple Computer's Mac-only application that has shipped as the default
browser on every Mac since version 10.3 (Panther). The current version of Safari at the time of
this writing is 2.0.
While Mac users are much less numerous than their Windows-based counterparts, Mac
sales have been on the rise for several years, and Safari is now estimated to account for over
5 percent of all web traffic. This might not seem like a lot, but it certainly is a percentage large
enough for most web developers to sit up and take notice. Safari usage has been on the rise
since its release, and doesn't show any signs of slowing down.
Safari is also known among standards-oriented web designers as a star citizen of the Internet,
handling CSS and (X)HTML as well as Firefox, and even besting Firefox by supporting a few
and deservedly so—but when it comes to rendering CSS, you can rely on Safari to treat you
browser for designers.
As Mozilla did with Firefox, Apple has released the rendering engine for Safari, which it
calls WebKit, under an open source license. WebKit itself is based on another open source proj-
ect called KHTML, a rendering engine with its roots in Linux, the KDE desktop environment,
and the Konqueror web browser. A handful of Mac-only browsers are based on WebKit, includ-
ing OmniWeb ( www.omnigroup.com/applications/omniweb/ ) and Shiira ( http://hmdt-web.net/
shiira/en ). WebKit also powers the web browser built into Nokia's latest line of cell phones, as
well as other mobile devices. In addition, many popular Mac programs whose primary purpose
is something other than web browsing use WebKit to render (X)HTML, CSS, and related content.
Programs that use WebKit generally render content identically to Safari.