Richard Bailey of the Cider team shows how simple it is to add spell-checking to your WPF TextBox and RichTextBox controls. Just set IsSpellCheckEnabled=”True” and your uses will see red squigglies when they mis-type a word! Right-clicking also provides a list of suggestions. Even cooler is that this is WPFs own spell-checking engine, and does not rely on MS Word. It does not contain a grammar checker.