UltimateSpell is a spell checker that you can add to any content editor, or to your website. Spell Check As You Type (underline spelling errors and correct with a right-click). Auto correct spelling errors. Alternatively display a spell check dialog box with the click of a button. Display text sentence-by-sentence. Spell check selected text only. Look up meaning in an online dictionary. Multilingual. Auto find all editable controls or specify the controls to spell check. Add words to custom dictionaries. Show synonyms in a popup context menu. Grammar check for intranet applications. Fast, accurate, and AJAX-enabled. Support Windows Forms .NET applications.