Für Firefox User gibt es ein mehr als reichhaltiges Angebot an nützlichen Erweiterungen, nach welchen sich User des IE7 nur die Finger lecken können. Allerdings sind mittlerweile auch endlich nützliche Add-Ons für den IE zu haben.

Internet Explorer Developer Toolbar
Gerade für Webentwickler mit Fireforx ist Firebug oder die Web Developer Toolbar ein unverzichtbares Werkzeug geworden. Mittlerweile gibt es jedoch auch ein änliches Werkzeug von Microsoft für den IE. Mit der Beta 3 der Internet Explorer Developer Toolbar (IEDT) wird der IE um ein paar nützliche Funktionen wie z.B. dem Testen oder Verändern von DOM-Inhalten einer Webseite, das Browser-Fenster auf eine vorgebene Bildschirmauflösung zu setzen oder die Anzeige von Informationen zu HTML-Objekten erweitert. Desweiteren erlaubt der IEDT das gezielte Löschen des Cache oder von abgelegten Cookie-Daten. Leider ist dieses Addon sowie alle folgenden nur in englischer Sprache verfügbar.
ieSpell
ieSpell is a free Internet Explorer browser extension that spell-checks text-input boxes on a Web page. It should come in particularly handy for users who do a lot of Web-based text entry (Web mail, forums, blogs, diaries). Even if your Web application already includes spell-checking functionality, this utility is faster than a server-side solution. Plus, you get to store and use your personal word list across all your applications instead of having to maintain separate ones on each application. Version 2.5.1 build 106 may include unspecified updates, enhancements, or bug fixes.

Inline Search
Inline Search is an extremely useful free add-on for Internet Explorer that mimics Firefox’s search behavior. It turns searching in a web page into a non modal research experience coupled with a find as you type facility. It integrates flawlessly into IE (version 5.5 or above), giving it that little extra that makes you a lot more efficient when you are looking for a specific piece of information.

IE7 Open Last Closed Tab
IE7 Open Last Closed Tab is a plug-in for Internet Explorer 7 that makes „Alt-X“ reopen the last closed tab. This is very useful when you accidentally close a tab that you didn’t mean to close. Instead of trying to find it in your browser history, you hit „Alt-X“ and it automatically reopens in a new tab.

Add Search Providers
Add Search Providers to add a provider to the Internet Explorer 7 Instant Search box.

Trailfire Toolbar
Trailfire Toolbar provides a unique new method for commentary, web navigation and social discovery. By leaving „marks“, which are essentially electronic notes, on individual Web pages and adding your comments you can guide people out onto the web and help them discover what you already know. Connect your marks together and form a „Trail“ with your own navigation path across the web. Trailfire’s unique social discovery engine generates an audience to discover the trails you create without the need for them to download the Trailfire extension. Download the Trailfire extension and create a web of your own for others to discover.Version 1.0.978 opens the ability to have conversations with your readers and opens a new social discovery engine to help create an audience for the trails you create.

StumbleUpon Toolbar
StumbleUpon Toolbar for Internet Explorer allows you to „channel surf“ the Internet and discover great Web sites and Web content according to your interests. Whether it’s a Web site, video, picture, game, blog, or wiki, StumbleUpon helps you find interesting stuff recommended by like-minded people with just a single click of the Stumble button. The more you use it, the better it gets. Join more than 1.3 million users who have rated more than seven million Web sites. All of the content recommended is found by other people who want to share their best finds and favorite sites. With StumbleUpon you can stumble the Internet for great Web sites, rate and review what you find, keep a history of the things you like, share the things you like with friends, and join groups of like-minded people.Version 2.011 may include unspecified updates, enhancements, or bug fixes.

GooglePreviewIE
GooglePreviewIE is an Internet Explorer (IE) toolbar that inserts preview images (thumbnails) of web sites and Amazon products into the Google and Yahoo search results pages. Thumbnails are provided by thumbshots.org and alexa.com.