SpellBound isn’t some new word from the world of Harry Potter. SpellBound is a spell checking plugin for Firefox, that uses the OpenOffice dictionaries.
After the plugin is installed the context menu of any textfield of textarea contains a new entry “Check Spelling” which opens a small new window containing the text from the clicked component, a combobox to choose the language from and the typical controls to navigate through the errors.
While having spell checking features directly integrated with the original data entry controls would be nice, this isn’t bad and it has a practical advantage. You can edit your text in the spell checker. So when a text area on a web page is too small you can open it in SpellBound, resize the SpellBound window to your liking and edit your text in a conveniently big textarea.