GtkSourceCompletion has been developed in C using GObject and Gtk+2. The library has been developed by Jesús Barbero Rodríguez <chuchiperriman at gmail dot com> using Ubuntu, Gnome, Gedit, git, subversion, vim, devhelp... Thanks all the people who make this possible!!!!
You can get the last source code using git from http://github.com/chuchiperriman/gtksourcecompletion/tree/master by doing:
git clone git://github.com/chuchiperriman/gtksourcecompletion.git
The project homepage is http://sourceforge.net/projects/gtksourcecomple/
You can report any bug in the sourceforge bug tracking and you can write a mail to me directly or using the gedit mail-list (http://projects.gnome.org/gedit)
If you want to learn how to use GtkSourceCompletion go to Documentation section