The best replacement for gui is cli.

The best alternatives to gui are rated as following:
★★★★★  cli
★★★★★  ui
★★★  command line
★★  cui
★★  api
★★  graphical user interface
★★  command line interface
★★  console
★  gooey
★  freepbx
★  ngui
★  tui
★  hud
★  dos
★  guilayout
★  cli difference
★  hmi
★  gui
★  console application
★  windows gui
★  adamantoise
  command
  terminal
  green screen
  web ui
  command line) and __
  dong quai
  ms dos
  zoss
  cpl gui

Your alternative for gui is not listed? Suggest!
Speaking about gui, one probably shouldn't forget about java.

Other search terms related to gui and their ratings are:
★★★★★ java
★★★★★ matlab
★★★★ c++
★★ eclipse
★★ powershell
★★ perl
★ qt
★ arduino
★ r
★ pygame
★ autohotkey
linux
x server
fortran
window manager
mfc
visual basic
You have in mind a companion for gui and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of gui in all years. Click on graph for more.
gui
cli
ui