GtkSpell provides MSWord/MacOSX-style highlighting of misspelled words in a
GtkTextView widget. Right-clicking a misspelled word pops up a menu of
suggested replacements.

GtkSpell is a library, to be used by your software.
GtkSpell depends on GTK+ 2.0 (of course), and also on Enchant
library, which can be found at http://www.abisource.com/projects/enchant/ .

For more information, see http://gtkspell.sf.net .