Comment by pwdisswordfishs

This is how GTK came about. Literally "GIMP Toolkit". They took the widgets that the GIMP creators had created, and turned it into a general-purpose toolkit for other apps to use, due to issues with Qt.

The comments about web stack stuff is probably off. Godot is already a pretty featureful UI framework + form designer that makes anything the "frontend" world has ever produced seem like they only had a fraction (1-to-10%) as much time and resources to build, compared to what Godot was already shipping in 1.0, (even though the reverse is true).