This is version 0.99.25 of the GNU Image Manipulation Program.

This version is no longer distributed along with the Gtk toolkit;
you'll have to grab and install it separately.  Please install Gtk
before configuring the GIMP for compilation. This GIMP requires
GTK 0.99.7 or later.

gimp-data-extras contains a bunch of optional extra data files for GIMP.

See the files README and NOTES in the archive for more details.