A collection of C extension syntax files for xlib, glib (gobject,
gio), gdk-pixbuf, gtk2 (gdk2), gtk3 (gdk3), atk, at-spi, pango, cairo,
clutter, gimp, gstreamer, dbus-glib, json-glib, libglade,
gtksourceview, gnome-desktop, libgsf, libnotify, librsvg, libunique,
libwnck, gtkglext, vte, poppler, evince.
The xlib one was originally created by Hwanjin Choe (vimscript #570),
the others were generated from gtk-doc declaration lists and support
enabling/disabling of highlighting of deprecated declarations.