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.
lrwxrwxrwx 1 root root 20 avr 22 10:47 /usr/lib/libgtkspell.so.0 -> libgtkspell.so.0.0.0 -rwxr-xr-x 1 root root 18832 avr 22 10:47 /usr/lib/libgtkspell.so.0.0.0