ASPNetSpell is an ASP.Net web forms spellchecking software that offers international spellcheck capabilities with MS Word-like behavior. It includes personal dictionaries and as-you-type features and is compatible with ASP.Net 2, 3, 3.5 & 4.

Moreover, AspNetSpell is fully integrated visually with Visual Studio .Net versions from 2003 to 2010. The code generated by the software is not only W3C HTML and XHTML compliant but also highly accessible, making it an ideal option for users.
Users familiar with MS Word's spellchecker will find AspNetSpell easy to navigate. The software comes with notable features such as grammar checking and personal dictionaries that make it convenient to use. Its "As-You-Type" in context spell checking with "red wiggly underlines" is a familiar feature that's easy to recognize.
From your ToolBox, you can now effortlessly drag and drop a spelling validation button into your web application forms. ASPNetSpell offers international spellchecking for any popular rich HTML control and any number of fields. You can also replace any TextBox with a SpellTextBox complete with As-You-Type spelling suggestions, which work on all major browsers.
To get started with ASPNetSpell, download and unzip it to your preferred location on your hard disk. Add the ASPNetSpell.dll to your Visual Studio toolbox, and copy the directory called AspNetSpell to the root folder of your website project. You don't have to add it to the application in Visual Studio.
Using the AspNetSpell.SpellButton is effortless. Drag it from the toolbox onto your ASPX web form in design mode, and it will render as a spell check button. If you face difficulties, help is readily available to guide you through the process.
Version 4.0.0.35: New:: ASP.Net,2,3 & 4 support with full Visual Studio 2003-2010 Integration. New: "Red underline" in-context spelling. Free:: Medical, Legal and Scientific Dictionaries.
Version 2.9: New:: ASP.Net 1,2&3 Support. Free Medical, Legal and Scientific Dictionaries. Visual Studio 2010 Coming Soon
Version 2.42: New Release: The AspNetSpell (Asp.Net SpellCheck) component provides international spell checking for your ASP.Net web forms. AspNetSpell is compatible with ASP.Net 1 and 2. The code it delivers is W3C HTML and XHTML compliant, and has a good degree of accessibility.
Version 2.0: New Release: The AspNetSpell (Asp.Net SpellCheck) component provides international spell checking for your ASP.Net web forms.