HTML and CSS Reference
For years Trident has supported HTML 4.01, XML 1.0, XSLT 1.0, and DOM Level 1 with minor implementation
gaps. CSS Level 2 and DOM Level 2 have been provided with major implementation gaps and conformance issues.
The CSS support in Windows Internet Explorer has constantly been evolving. Internet Explorer 6 was the first version
with full CSS Level 1 compliance. However, some selectors such as min-height were missing. Internet Explorer 8 is
the first IE version with nearly complete CSS 2.1 and partial CSS3 support. The CSS features introduced in Internet
Explorer 8 worked only if the web pages were rendered in IE8 mode (or higher). This was ensured by adding the meta
tag described in Listing 1-1 to the head section of web pages, which should be avoided.
Listing 1-1. Version Targeting for Internet Explorer 8 (Should Not Be Used)
<meta http-equiv="X-UA-Compatible" content="IE=8" />
Since Trident version 4 (used by IE8), a built-in RSS/Atom news feed reader is also available through a dedicated
button with the RSS logo.
Microsoft recently recognized the importance of standards support and has begun to take it seriously. First,
Microsoft became an active participant in standards development in the CSS3 and SVG Working Groups at W3C.
Second, it is a co-chair of the HTML5 Working Group and a leader in the HTML5 Testing Task Force.
Trident 5 applied in Internet Explorer 9 introduced support for modern web standards, including HTML5,
CSS3, ECMAScript5, DOM Levels 2 and 3, ICC Color Profiles, and SVG . Trident 5 introduced a new hardware-
accelerated JScript engine called Chakra. In contrast to earlier versions that can render only “HTML-compatible”
XHTML documents served incorrectly with the text/html MIME-type, Trident 5 provides full XHTML support.
Trident 6 (IE 10) had improved HTML5, CSS3, and EcmaScript5 support, and interoperable HTML5 Quirks Mode.
The major HTML5 improvements were support for the async attribute on HTTP/2 elements, Drag and Drop, File API,
Sandbox, Web Sockets, Web Workers, some Web Performance APIs, HTML5 Video Text Captioning, local storage with
IndexedDB and the HTML5 Application Cache. As for CSS, Trident 6 added support for CSS3 multi-column layout,
grid layout, and flexible box layout, positioned floats, CSSOM Floating Point Value, Media Queries, 3D Transforms, text
shadow, transitions, transforms, animations, gradients, and the font-feature-settings property to access advanced
Resource Sharing (CORS) for XMLHttpRequest.
IE 11 (powered by Trident 7) supports WebGL and Google's SPDY open networking protocol. HTML5 support has
further improved, including new features such as HTML5 full screen, HTML5 prerender, and HTML5 prefetch. Other
Firefox, Camino, the Mozilla Application Suite, Netscape, Thunderbird, SeaMonkey, and other software apply the
rendering engine Gecko (originally NGLayout) . Netscape released the first version in 1997. In 1998, the Mozilla
project was launched, and the source code was released under an open source license. Gecko is now developed by the
Mozilla Foundation/Corporation. It is written in C++ 7 as a cross-platform layout engine under three licenses:
Mozilla Public License (MPL), GNU General Public License (GPL), and GNU Lesser General Public License (LGPL).
Gecko was originally designed with web standards support in mind and the standards implementation is
ECMAScript 3 and 5, DOM Levels 1/2/3, XML 1.0 and 1.1, SMIL, MathML, RDF, RDDL, XSLT 2.0, XSL-FO 1.0,
XInclude, XForms, XFrames, XPath 2.0, GraphML and GML/XGMML, SVG 1.1, and Animated PNG (APNG)
images with alpha transparency.Gecko supports DOCTYPE switching for backward compatibility, making it possible
to render nonstandard web sites designed for older browsers correctly. Older Internet Explorer issues such as the
incorrect implementation of the document.all property or the marquee element are also handled.