Internet Explorer may not have the vast library of extensions offered by Firefox or Chrome, but there are a host of useful tools available to help you get things done, ranging from full scale add-ons to unobtrusive accelerators and bookmarklets. Here's a selection of the best.
5. Bing Translator: Allows you to quickly translate entire web page with the click of a mouse using Bing. Some people actually think that Microsoft Translator is more accurate than either Google Translator or Babelfish. There's a Google Translate accelerator available, too, for those who prefer it.
4. Wolfram Alpha: Available as a toolbar and a full scale add on in addition to an Accelerator, Wolfram Alpha is available for all of the major browsers. It allows you to easily access Wolfram Alpha's computations without having to navigate to the site. It does everything from quick fact checks to complex math problems.
3. Readability: While it doesn't support a full accelerator, this is a handy bookmarklet. Readability allows you to remove all of the adds and clutter from a webpage for easy reading, similar to Safari's Reader. Although the free version doesn't have all the features of the paid one, it does support a variety of formatting options, and should be a part of anyone's browser. Also available for Safari, Firefox, and Chrome.
2. Find with Wayback Machine: Never worry about dead links again. Using this accelerator, you can access any website in the Internet Archive's 85 billion page archive, all the way back to 1996.
1. Speckie: The one add on that no one should be with out. Speckie is a spell checker that works just like a native feature. Once you've installed it, you'll never know that it's there. Right click misspelled words to easily correct them and there, one of IE's most glaring omissions is fixed.
There are many more add-ons, including alternatives to the ones listed above, available at the IE Gallery.