What is WebKit and how is it related to CSS?

Update: So apparently, WebKit is a HTML/CSS web browser rendering engine for Safari/Chrome. Are there such engines for IE/Opera/Firefox and what are the differences, pros and cons of using one over the other? Can I use WebKit features in Firefox for example?

Every browser is backed by a rendering engine to draw the HTML/CSS web page.

IE → Trident (discontinued)

Edge → EdgeHTML (clean-up fork of Trident) (Edge switched to Blink in 2019)

Firefox → Gecko

Opera → Presto (no longer uses Presto since Feb 2013, consider Opera = Chrome, therefore Blink nowadays)

Safari → WebKit

Chrome → Blink (a fork of Webkit).

See Comparison of web browser engines for a list of comparisons in different areas.

The ultimate question... is WebKit supported by IE?

Not natively.

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Addition to what @KennyTM said:

IE Engine: Trident CSS-prefix: -ms

Engine: Trident

CSS-prefix: -ms

Edge Engine: EdgeHTML → Blink3 CSS-prefix: -ms

Engine: EdgeHTML → Blink3

CSS-prefix: -ms

Firefox Engine: Gecko CSS-prefix: -moz

Engine: Gecko

CSS-prefix: -moz

Opera Engine: Presto → Blink1 CSS-prefix: -o (Presto) and -webkit (Blink)

Engine: Presto → Blink1

CSS-prefix: -o (Presto) and -webkit (Blink)

Safari Engine: WebKit CSS-prefix: -webkit

Engine: WebKit

CSS-prefix: -webkit

Chrome Engine: WebKit → Blink2 CSS-prefix: -webkit

Engine: WebKit → Blink2

CSS-prefix: -webkit

¹⁾ On February 12 2013 Opera (version 15+) announces they moving away from their own engine Presto to WebKit named Blink.

²⁾ On April 3 2013 Google (Chrome version 28+) announces they are going to use the WebKit-based Blink engine.

³⁾ On December 6 2018 Microsoft (Microsoft Edge 79+ stable) announces they are going to use the WebKit-based Blink engine.

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Webkit is a web browser rendering engine used by Safari and Chrome (among others, but these are the popular ones).

The -webkit prefix on CSS selectors are properties that only this engine is intended to process, very similar to -moz properties. Many of us are hoping this goes away, for example -webkit-border-radius will be replaced by the standard border-radius and you won't need multiple rules for the same thing for multiple browsers. This is really the result of "pre-specification" features that are intended to not interfere with the standard version when it comes about.

For your update:...no it's not related to IE really, IE at least before 9 uses a different rendering engine called Trident.

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This has been answered and accepted, but if someone is still wondering why are things a bit messed up today, you'll have to read this:

http://webaim.org/blog/user-agent-string-history/

It gives a good idea of how gecko, webkit and other major rendering engines evolved and what led to the current state of messed up user-agent strings.

Quoting the last paragraph for TL;DR purposes:

And then Google built Chrome, and Chrome used Webkit, and it was like Safari, and wanted pages built for Safari, and so pretended to be Safari. And thus Chrome used WebKit, and pretended to be Safari, and WebKit pretended to be KHTML, and KHTML pretended to be Gecko, and all browsers pretended to be Mozilla, and Chrome called itself Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/525.13 (KHTML, like Gecko) Chrome/0.2.149.27 Safari/525.13, and the user agent string was a complete mess, and near useless, and everyone pretended to be everyone else, and confusion abounded.

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-webkit- is simply a group that Chrome, Safari, Opera and iOS browsers fit into. They all have a common ancestor, so often their capabilities/limitations (when it comes to running CSS and Javascript) are confined to the group.

A developer will place -webkit- followed by some code, meaning that the code will only run on Chrome, Safari, Opera and iOS browsers. Here is a complete list:

-webkit- (Chrome, Safari, newer versions of Opera, almost all iOS browsers (including Firefox for iOS); basically, any WebKit based browser)

-moz- (Firefox)

-o- (Old, pre-WebKit, versions of Opera)

-ms- (Internet Explorer and Microsoft Edge)

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The ultimate question... Is WebKit supported by IE?

Kind of. Check out Chrome Frame, it's a plugin for Internet Explorer that makes it use the Webkit engine. The only quirk is that you have to persuade your visitors to install the plugin.

Update

Chrome Frame is no longer maintained or supported…

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WebKit is a layout engine designed to allow web browsers to render web pages. The WebKit engine provides a set of classes to display web content in windows, and implements browser features such as following links when clicked by the user, managing a back-forward list, and managing a history of pages recently visited. WebKit was originally created as a fork of KHTML as the layout engine for Apple's Safari; it is portable to many other computing platforms. It is also used in Google's Chrome Browser. WebKit's WebCore and JavaScriptCore components are available under the GNU Lesser General Public License, and the rest of WebKit is available under a BSD-style license.

Source Wikipedia

For further information about layout engines you can look here

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Webkit is an HTML rendering engine used by Chrome and Safari.

It supports a number of custom CSS properties that are prefixed by -webkit-.

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Webkit is the html/css rendering engine used in Apple's Safari browser, and in Google's Chrome. css values prefixes with -webkit- are webkit-specific, they're usually CSS3 or other non-standardised features.

to answer update 2 w3c is the body that tries to standardize these things, they write the rules, then programmers write their rendering engine to interpret those rules. So basically w3c says DIVs should work "This way" the engine-writer then uses that rule to write their code, any bugs or mis-interpretations of the rules cause the compatibility issues.

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Webkit is the rendering engine used in the popular browsers Safari and Chrome, as well as others.

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A common problem I have ran into as a website designer is that alot of people use IE6+. No big deal usually, except in CSS I have to add multiple rendering syntax' to parse each request, per browser. It would be very nice if there was a universal rendering setup for CSS that IE can read as easily as Chrome/FF/Opera and webkit. The problem with IE is that if I do NOT use ALL the proper CSS styles and rendering, than my websites look and work great using every browser except IE. This can make for an unhappy, die-hard IE customer.

Example is this: Let us say I need a 1px, grey border with a border-radius of 10%. For Chrome and others, I use the webkit property. Now, for IE, I have to add seperate CSS styles using the simple old CSS values of "border: 1px solid #E5E5E5" and "border-radius: 10%". A positive outcome is not always guaranteed over all IE browser versions, but for the most part this method works fine for me and many others.

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Even though this is an older post, there is also another method to rendering for older versions of Internet Explorer. -webkit while being a CSS Vendor Prefix, you can also download a few JS applications and place them in the bottom of the HTML's HEAD.

Try using Modernizr, HTML5 Shiv and Respond.js. These are amazing IE compatible polyfill scripts that use polyfills, and other resources which will help better render HTML5 elements in IE9 and Below.

To use these polyfills, simply add HTML boolean logic to place them, IF the browser is less than the desire IE version. Example code is:

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Webkit is the rendering engine used in the popular browsers Safari and Chrome, as well as others Every browser is backed by a rendering engine to draw the HTML/CSS web page.

IE → Trident (discontinued) Edge → EdgeHTML (clean-up fork of Trident) Firefox → Gecko Opera → Presto (no longer uses Presto since Feb 2013, consider Opera = Chrome nowadays) Safari → WebKit Chrome → Blink (a fork of WebKit).

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A good documentation about WebEngines especially webKit and its developers you can read at: WebKit

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