There are three glade files in Dr. Geo that are used for designing the interface.
I have changed two files: drgeo2.glade and drgeoMDI.glade.
They have been modified to use GtkBuilder format instead of the earlier format, i.e libglade.
GtkBuilder simply re-thinks the internal workings to make it more versatile and adhere to standards and package it along with the rest of the GTK+ library. Read more here.
I need to revamp more stuff because even though it should build fine right now with GTK+ 2.24 using GtkBuilder APIs, it still has to be completely migrated from the older format including the callbacks.