An Internet Explorer shell is computer software that uses the Trident rendering engine of Internet Explorer. Although the term Trident shell is probably more accurate for describing these applications, including Internet Explorer itself, the term Internet Explorer shell or IE shell is in common parlance. This means that these software products are not actually full-fledged web browsers, but are simply an alternate interface for Internet Explorer. They share the same boundaries of the Trident engine.

Examples

Some of the more popular Internet Explorer shells include the following:

AOL Explorer

Avant Browser

Browzar

Enigma Browser

Foxie

iRider

Maxthon

MSN Explorer

NetCaptor

Netscape Browser 8.x (uses both Trident and Gecko)

Slimbrowser

Souvergin

TrustyFiles

WebbIE

Web Explorer X

These applications supplement some of Internet Explorer's usual user interface components for browsing, adding features such as popup blocking and tabbed browsing. For example, MSN Explorer can be thought of an Internet Explorer shell, in that it is essentially an expansion of IE with added MSN-related functionality. A more complete list of Trident-based browsers can be found under the list of web browsers.

Non-browser shells

Other applications that aren't primarily for web browsing, such as Intuit's Quicken and QuickBooks, AOL, Winamp, and RealPlayer, use the rendering engine to give a limited-functionality "mini" browser within their own user interfaces.

On Windows, components of Internet Explorer are also used in Windows Explorer, the operating system shell that provides the default file system browsing and desktop services. For example, folder views in Windows Explorer on versions of Windows prior to Windows XP utilize IE's DHTML processing abilities; they are essentially little web pages. Active Desktop technology is another example.

The Trident engine was, until recently also used to render HTML portions of email messages in Microsoft Outlook and Outlook Express email clients (Outlook 2007 now uses Microsoft Word to render HTML e-mail). This integration, while convenient, is an often-exploited "back door," since the Internet Explorer components make available more functionality to the HTML code than some feel should be permitted in the context of email messages, and Outlook and Outlook Express have, historically, not done enough to prevent malicious code from taking advantage of that functionality. The latest updates for Outlook Express, which require Windows XP and are distributed with Service Pack 2, are intended to improve this situation. Outlook 2003 already includes many of the updates.

While all of these programs can customize Internet Explorer's user interface and extend the feature set, they can't modify the rendering engine, and are therefore subject to many of the same benefits and vulnerabilities of IE, including security holes and issues with rendering.

HTA is a process developed by Microsoft to open up HTML files in a window free of navigation and other interface elements.

Shell-like extensions to IE

In addition to programs using Internet Explorer's rendering engine, there are also programs that add features to Internet Explorer. The methods they use to add features can blur the distinction between a shell, plug-in, or toolbar. Examples include the following:

IEWatch , which provides diagnostic panes for monitoring HTTP traffic, HTTP search and filtering, HTTP performance charts and the ability to view the DOM and quickly modify the HTML, style sheets and scripts of any web page to test code.

PageEngage an HTTP analysis tool which allows a user to view all HTTP headers, provides a script console for fully interacting with the Document Object Model of IE, and additionally provides the user the ability to modify the response content before the browser renders it.

iMacros , is a web macro recorder enhancement, that adds record & replay and VBA support to IE.

Kimba Kano, which adds a context menu option to do various kinds of web searches for a currently highlighted term

HttpWatch , is an HTTP sniffer and debugger for Internet Explorer that displays information about headers, cookies, redirection and compression

IE7Pro is a plugin for Internet Explorer 7/6 giving it extra features such as AD blocking, user scripting, spell check, flash blocker, amongst others.

WebReplay is an IE plug-in for browser automation and web testing. With WebReplay you can fill web forms and automate web applications along with many other activities.