Author and maintainer of gspell:
Sébastien Wilmet <swilmet@gnome.org>

The code comes from the gedit spell plugin, which was primarily written by:
Paolo Maggi
Paolo Borelli
Jesse van den Kieboom
Ignacio Casal Quinteiro
Sébastien Wilmet

The inline checker for GtkTextView originally comes from an old version of
GtkSpell, which was written by:
Evan Martin