Visual Studio Spell Checker

Mikhail Arkhipov (MSFT)'s WebLog : Spell Checker for HTML and ASP.NET pages: "Spell checker works in Source view, it is able to extract text from markup elements and use Office 2003 spell checker to check the text. Spell checker is able to handle entities to some extent (they are considered whitespace for now). It is also able to spell check values of attributes that typically contain human readable text."