It's Tcl/Tk see: https://www.tcl.tk/
tkinter is a wrapper around tk. So this is bypassing that step.
The concept was started back in 1987, with the actual Tk being started late 1988.
tkinter is a wrapper around tk. So this is bypassing that step.
The concept was started back in 1987, with the actual Tk being started late 1988.