Best graphical interface designer under X11?
 

Hello,

You are maybe looking a comfortable interface designer sofware. So, what is the best graphical interface designer under X11?

The restriction is the number of dependencies, which are/must be installed.

(ex: you may check the gtk-dev deb on debian to have an idea)

FLUID DESIGNER IS LIKELY THE BEST, isn't it? Are they more possible recommendations?

Even for DOS:
https://sourceforge.net/p/fltk-dos/wiki/Screenshots/

it all depends on what Programming Language you want to use.
Wouldn't it?

everyone has its own IDE if someone wrote one for it.