ieSpell

ieSpell is a free Internet Explorer browser extension that spell checks text input boxes on a webpage. It should come in particularly handy for users who do a lot of web-based text entry (e.g. web mails, forums, blogs, diaries). Even if your web application already includes spell checking functionality, you might still want to install this utility because it is definitely much faster than a server-side solution. Plus you get to store and use your personal word list across all your applications, instead of maintaining separate ones on each application.

The program installs as a new button in the IE toolbar

• Completely standalone spell checker for your web browser. Does not require Microsoft Office or any other third party components.
• Integrates flawlessly with Internet Explorer and other IE based browsers.
• Three ways to start the spell check; via the right click context menu, the toolbar or the menu bar.
• Supports a wide range of web applications including simple text forms, rich text editors, forums, blogs, webmail (including Outlook Web Access and Lotus iNotes) and more!
• Spell check in any of the 3 variants (US, UK and Canadian) of the English Language!
• Suggestions are sorted by the degree of closeness with the misspelled word.
• Intelligent suggesting for misspelled words using typographic “looks like” matching.
• Easily add/remove your personal words in ieSpell via an intuitive user interface!
• Organise your personal words in individual custom dictionaries! Share them with your friends and co-workers over the network!
• Integrates with Microsoft Office's proofing tools. Have ieSpell share the same copy of the custom dictionary so that when you add/remove your personal words in ieSpell, the same is reflected in Microsoft Office and vice versa!
• ieSpell suggested a word that you are not familiar with? Look up its meaning in an online dictionary!
• Powerful API for web application developers.
• Force users to spell check the document before submission.
• Ignore certain text fields.
• Refuse a form submission if the user cancels the spell check!