Lazarus (kinda of a Delphi clone that also uses Object Pascal) is probably the best way to make cross platform native desktop applications that actually uses the native GUI toolkit for each platform.
I hear it is quite popular for creating GUIs wrappers for CLI tools.
Yup. If you write your tool as mostly library with the main function just calling into your .so/.dll then the work to make a gui version of your program is minimal.
I hear it is quite popular for creating GUIs wrappers for CLI tools.