Comparison of layout engines (Non-standard HTML)

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HTML and HTML5 Dynamic HTML XHTML XHTML Mobile Profile and C-HTML Character encodings Font family HTML editor HTML element HTML scripting Layout engine Quirks mode Style sheets Unicode and HTML W3C Web colors Comparison of document markup languages web browsers layout engines for HTML HTML5 Non-standard HTML XHTML

The following tables compare deprecated and proprietary HTML elements and attributes compatibility and support for a number of layout engines. Please see the individual products' articles for further information. This article is not all-inclusive or necessarily up-to-date. Unless otherwise specified in footnotes, comparisons are based on the stable versions without any add-ons, extensions or external programs.

In the early years of the World Wide Web, the standards which today are used in most web browsers and web pages were mostly non-existent. Different browsers and HTML editors were being offered by competing vendors such as Netscape, Microsoft and WebTV, all of whom possessed their own ideas for how web sites should be constructed. These varying standards resulted in web developers coding for specific web browsers, using elements which could often be recognized by only one browser.

Explanation of the tables

Engine nomenclature

Rather than the names of web browsers, the names of the underlying engines are used. The browsers that use the various engines are listed below.

Layout engine	Used by
Trident	Internet Explorer and other Internet Explorer shells (Microsoft Windows operating systems only)
Tasman	Mac OS X versions of Internet Explorer and MSN
Gecko	All Mozilla software, including Firefox; SeaMonkey; Galeon; Camino; K-Meleon; Flock; also Epiphany-gecko
WebKit	Apple Safari; Google Chrome; Shiira; iCab 4; OmniWeb 5.5+; Epiphany; Adobe AIR; Midori; Adobe Dreamweaver CS4
KHTML	Konqueror
Presto	Opera; Opera Mobile, Nintendo DS Browser; Internet Channel; future Adobe Systems products
iCab	iCab 1-3
Prince XML	Prince

Values

Values indicate the level of support in the most recent version of the layout engine, or (if a version number is given) in the specified version. Version numbers without any other value indicate the version at which the layout engine first fully supported the feature.

Value	Meaning
Yes	Indicates that the layout engine fully supports this property/element when valid values are used.
No	Indicates that the property/element is completely ignored.
Partial	Indicates that the property/element is understood, but that not all values are supported. Supported values are implemented correctly.
Incorrect	Indicates that the property/element is understood, but that it is not implemented correctly in all cases.
Experimental	Indicates that the property/element is understood, but supported under an alternate name. May be incomplete or buggy.
Dropped	Indicates that the property/element is no longer supported.
Nightly build	Indicates that the property/element is supported to some extent in an experimental/nightly build. Future support is expected.

Deprecated HTML elements

Element	Function	Supported first by	Deprecated in HTML version	Alternative solution	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
applet	Insert an applet	HotJava	4	embed, object	4.0	Yes	1.7	Yes	Yes	7.0	Yes
basefont	sets font styles	Internet Explorer	4	CSS Styles: font-family, color, font-size	2.0	Yes	No	1.0	Yes	Yes	?
blackface	Used to display text in a double-weight bold font face	WebTV	—	Alternate fonts, CSS style: font-weight	No	No	No	No	No	No	No
center	centers its contents	Netscape	4	CSS styles: text-align:center; (text), margin-left:auto; margin-right:auto; (block elements with set width)	Yes	?	Yes	Yes	Yes	Yes	?
dir	directory list	—	4	ul, ol	Yes	?	Yes	Yes	Yes	Yes	?
font	applies font styles	Netscape	4	CSS styles: font-family, color, font-size	Yes	?	Yes	Yes	Yes	Yes	?
isindex	adds a search field	—	4	form, input type="text"	5.5	?	1.7	1.3	Yes	Partial	?
listing	displays preformatted text	IETF	2	pre, samp, code, CSS styles: font-family:monospace;, white-space with the value pre, pre-wrap or pre-line	1.0	?	1.7	1.2	3.3	Yes	?
menu	menu list	—	4	ul, ol	Yes	?	Yes	Yes	Yes	Yes	?
plaintext	Designates that all HTML be ignored, and to display the page as is	—	3.2	the text/plain MIME type	Yes	?	Yes	Yes	Yes	Yes	?
s	strike through	—	4	del, CSS styles: text-decoration:line-through	4.0	Yes	1.7	Yes	Yes	7.0	Yes
shadow	Adds shadow to text	WebTV	—	CSS 3 Style: text-shadow	No	No	No	No	No	No	No
strike	strike through	—	4	del, CSS style: text-decoration:line-through;	4.0	Yes	1.7	Yes	Yes	7.0	Yes
u	underline	—	4	CSS style: text-decoration:underline;	4.0	Yes	1.7	Yes	Yes	7.0	Yes
xmp	Similar to pre and plaintext, but ignores all HTML within and displays as is.	—	2	pre, samp, code	1.0	?	1.7	1.2	3.3	4.0	?

Deprecated HTML attributes

Attribute	Element	Alternative solution	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
align	caption, div, fieldset, h1, h2, h3, h4, h5, h6, hr, img, input, legend, p, object, table	CSS	Yes	?	Yes	Yes	Yes	Yes	?
alink	body	CSS	Yes	?	Yes	?	Yes	Yes	?
background	body	CSS	Yes	?	Yes	?	Yes	Yes	?
bgcolor	body, table, td, tr, th	CSS	Yes	?	Yes	?	Yes	Yes	?
border	img, object	CSS	Yes	?	Yes	?	Yes	Yes	?
clear	br	CSS	Yes	?	?	?	Yes	Yes	?
compact	dl, ol, ul	CSS	No	?	No	?	Yes	Yes	?
color	basefont, font	CSS	Yes	?	Yes	?	Yes	Yes	?
height	td, th	CSS	Yes	?	Yes	?	Yes	Yes	?
hspace	img, object	CSS	Yes	?	Yes	?	Yes	Yes	?
language	script	Attribute type	Yes	?	No	?	Yes	?	?
link	body	CSS	Yes	?	Yes	?	Yes	Yes	?
noshade	hr	CSS	Yes	?	Yes	Yes	Yes	Yes	?
nowrap	td, th	CSS	Yes	?	Yes	?	Yes	Yes	?
size	basefont, font, hr	CSS	Yes	?	Yes	Yes	Yes	Yes	?
text	body	CSS	Yes	?	Yes	?	Yes	Yes	?
type	li, ul, ol	CSS	Yes	?	Yes	Yes	Yes	Yes	?
version	html	DTD declaration	Yes	?	?	?	No	?	?
vlink	body	CSS	Yes	?	Yes	?	Yes	Yes	?
width	hr, pre, td, th	CSS	Yes	?	Yes	Yes	Yes	Yes	?
vspace	img, object	CSS	Yes	?	Yes	?	Yes	Yes	?

Proprietary HTML elements

Tag	Function	Supported first by	Alternative solution	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
animate	loads a series of images which are then used as a replacement of the throbber animation.	IBM WebExplorer	Template:N/a	No	No	No	No	No	No	No
audioscope	Used to display the audioscope, a graphical display of sound waves	WebTV	Flash, SVG, Canvas	No	No	No	No	No	No	No
bgsound	Used to add sound to the background of a website	Internet Explorer	audio	2.0	Yes	No	No	No	5.12	?
blink	Used to display a blinking text	Netscape	CSS Style: text-decoration:blink	No	No	1.7	No	No	7.2	?
bq	Used to display a blockquote	WebTV, HTML 3.0	blockquote	No	?	No	No	No	No	?
comment	Used to allow the addition of comments to HTML documents	Internet Explorer, WebTV	<!-- ... -->	Yes	?	No	No	No	No	?
fn	Footnotes	WebTV, HTML 3.0	a href="#anchor" combined with element id="anchor" where anchor is a valid id	No	?	No	No	No	No	?
ilayer	Inline layers	Netscape (4 only)	iframe	No	No	No	No	Partial	No	?
image	Synonym of img	—	img	Yes	?	Yes	Yes	Yes	Yes	?
layer	Used to create multiple layers of text and images which lay on top of each other in a given order	Netscape (4 only)	CSS styles: position, z-index, iframe, AJAX	No	No	No	No	Partial	No	?
limittext	Used to set the width of the text display	WebTV	CSS style: width	No	?	?	?	No	No	?
marquee	Used to display a scrolling, marquee-like text.	Internet Explorer, WebTV	JavaScript, CSS 3 Style: marquee	Yes	Yes	1.7	1.2	3.3	7.2	?
multicol	Used to format and display multiple columns of text and images	Netscape	CSS 3 Style: columns	No	No	No	No	No	No	?
nobr	Prevents any line breaks from occurring within the flow of a text	—	CSS style: white-space:nowrap	Yes	?	Yes	Yes	Yes	Yes	?
noembed	Displays an alternative text for browsers which do not recognize the embed tag	Netscape	Child elements of object used as fallback	Yes	Yes	Yes	Yes	Yes	Yes	Yes
nolayer	Displays an alternative text for browsers which do not recognize the layer and ilayer elements	Netscape	Template:N/a	Yes	Yes	Yes	Yes	Yes	Yes	Yes
nosmartquotes	Prevents regular single '...' and double "..." quotes from automatically being replaced with smart single ‘...’ and smart double “...” quotes	WebTV	Template:N/a	No	No	No	No	No	No	?
sidebar	Creates a sidebar window that displays control elements.	WebTV	Template:N/a	No	No	No	No	No	No	No
spacer	Adds whitespace between words	Netscape	CSS style: padding, margin &nbsp;	No	No	Yes	No	No	No	?
sound	Used to add sound to the background of a website	Mosaic	audio	No	No	No	No	No	No	No
wbr	Placed inside a nobr element to add a line break	—	UTF-8-separator	2.0–7.0	Yes	1.7	Yes	3.1	No	?
xml	Delimits an XML data island inside an HTML page	Internet Explorer	?	Yes	Yes	?	?	No	?	?

Proprietary HTML attributes

attribute	Deprecated if used in tag	Function	Supported first by	Trident	Tasman	Gecko	WebKit	KHTML	Presto	iCab
autoactivate	select	viewer selects the list, it is activated automatically	WebTV	No	?	?	?	?	No	?
bgproperties	body	Determines whether background image scrolls with the background	Internet Explorer	Yes	?	?	?	Yes	No	?
bordercolor	body	Sets colors for 3-D table borders in the table, td, th, and tr elements	Internet Explorer	Yes	?	?	?	Yes	No	?
bordercolordark	body	Sets colors for 3-D table borders in the table, td, th, and tr elements	Internet Explorer	Yes	?	?	?	No	No	?
bordercolorlight	body	Sets colors for 3-D table borders in the table, td, th, and tr elements	Internet Explorer	Yes	?	?	?	No	No	?
controls	img	Uses the image tag to place video or audio clips	Internet Explorer	Yes	?	?	?	No	No	?
dynsrc	img	Uses the image tag to place video or audio clips	Internet Explorer	Yes	?	?	?	No	No	?
event	script	Defines function to call for an object.	Internet Explorer	Yes	?	?	?	?	?	?
for	script	Defines the object to bind a scripting event.	Internet Explorer	Yes	?	?	?	?	?	?
frame	table	Controls the display of the outer borders of a table in the table tag	Internet Explorer	Yes	?	?	?	Yes	No	?
framespacing	frameset	Sets the amount of space between frames	Internet Explorer	Yes	?	?	?	No	No	?
ibmlogo	img	used to show some internal mini images	IBM WebExplorer	No	No	No	No	No	No	No
internal-gopher-menu	img	used to show some internal mini images	IBM WebExplorer	No	No	No	No	No	No	No
left_arrow	img	used to show some internal mini images	IBM WebExplorer	No	No	No	No	No	No	No
leftmargin	body	Sets the margin between the browser window and the contents of the page	Internet Explorer	Yes	?	?	?	Yes	No	?
loop	img	Uses the image tag to place video or audio clips	Internet Explorer	Yes	?	?	?	No	No	?
red_bullet	img	used to show some internal mini images	IBM WebExplorer	No	No	No	No	No	No	No
rightmargin	body	Sets the margin between the browser window and the contents of the page	Internet Explorer	Yes	?	?	?	No	No	?
start	img	Uses the image tag to place video or audio clips	Internet Explorer	Yes	?	?	?	No	No	?
target	form	Specifies a target window or frame for the output of a form	Internet Explorer	Yes	?	No	?	Yes	No	?
usestyle	caption	???	WebTV	No	?	?	?	No	No	?
valign	caption	Sets vertical alignment of table caption	Internet Explorer	Yes	?	?	?	No	No	?

References

• DevGuru HTML - Non-standard elements
• OS/2 Web Explorer's proprietary HTML elements
• MSDN Handling Events with HTML elements

See also

• Web standards
• Wireless Markup Language