HTML and CSS Reference
Firefox also provides Google's Safebrowsing protocol to improve the security of data exchange.
Firefox does not support ActiveX controls by default. Although third-party plug-ins are available, they do not
work safely in all versions and under all platforms.
KHTML is the layout engine used by Konqueror. It supports HTML 4.01 and HTML 5. Both screen and paged media
support is provided for CSS 2.1. Beyond the full implementation of CSS 3 selectors (from KDE 3.5.6 ), KHTML
supports other CSS3 features, for example, multiple backgrounds, box-sizing, and text-shadow . KHTML supports
formats PNG, MNG, JPEG, GIF, and SVG).
The forked (adopted) version of KHTML is the open source WebKit layout engine. The most well-known browser
that uses WebKit is Apple Safari. Google Chrome used WebKit until version 27. Further browsers that use(d) WebKit
are Amazon Kindle, Arora, Midori, OmniWeb, Shiira, iCab (4+), Epiphany, SRWare Iron, and Maxthon (3+). WebKit
has been used on several mobile devices such as the Apple iPad, iPhone, and iPod Touch, as well as the browser on
Android, Palm webOS, and Symbian S60. The desktop version of Safari is available for both Apple and
Being one of the first implementers of the latest standards (which have also been proved by the Acid2 and Acid3
tests), Safari has always been considered as one of the most innovative web browsers. Safari 5, for example, was
amongst the first browsers that supported the newly introduced HTML5 features such as Media Support, full-screen
playback for the video element, canvas , Geolocation, structuring elements, Ajax history, the draggable attribute,
forms validation, the sandbox attribute, and Ruby annotation. Safari 5 handled CSS animations, CSS effects, and Web
accessibility features have also been introduced in Safari 5 such as VoiceOver Screen Reader, ARIA Support,
enhanced keyboard navigation, full-page zoom, content zoom, closed captions for HTML5 video, custom style sheets,
and minimum font size. It also had a built-in news feed reader . These features have further been improved in
The very first version of the other popular browser that used the WebKit rendering engine, Google Chrome, passed
the Acid1 and Acid2 tests, indicating good web standards support. Chrome passes the Acid3 test from version 4.
Presto was the rendering engine used by the Opera Desktop browser from version 7 to 15, along with the Opera
Devices SDK, and the Opera Mobile and Mini variants. Opera served as the basis for other browsers such as Nintendo
DS and DSi, Nokia 770, and Wii Internet Channel, as well as the browser for Sony Mylo COM-1.
One of the reasons for Presto's good web standards support was Opera Software's W3C membership . Opera
was amongst the first browsers with HTML5 support covering the canvas, video , audio , web forms, contentEditable ,
the input attribute and the input type, the viewport meta element, and HTML5 APIs like Web Workers, Geolocation,
Selectors, Touch Events, as well as CSS3 selectors, SVG, and SMIL .
The Blink rendering engine, announced in April 2013, is a fork of Webkit and used in Google Chrome 28+, Opera 15+,
Webview (Android 4.4+), RockMelt, and Amazon Silk. Blink has excellent HTML5 and CSS3 support, and it deprecates
vendor prefixes used in non-standard style sheets.