@Pygoscelisadeliae i think they dropped any acronym meaning
"GTK was originally designed and used in the GNU Image Manipulation Program (GIMP) as a replacement of the Motif toolkit; at some point Peter Mattis became disenchanted with Motif and began to write his own GUI toolkit named the GIMP toolkit and had successfully replaced Motif by the 0.60 release of GIMP.[40] Finally GTK was re-written to be object-oriented and was renamed GTK+.[41] This was first used in the 0.99 release of GIMP. GTK was subsequently adopted for maintenance by the GNOME Foundation, which uses it in the GNOME desktop environment."
https://en.m.wikipedia.org/wiki/GTK