And there's nothing special about Tcl the language that makes it special for scripting GUIs -- some people just put in the work to make a cross-platform GUI library and now everyone using Tcl benefits from it. I really wish Go had something similar to Tcl/Tk. I know making a cross-platform GUI library is hard, so how did Tcl/Tk's authors do it? All the way back in 1991, which still works even today?