The best replacement for ui is ux.

The best alternatives to ui are rated as following:
★★★★★  ux
★★★★  gui
★★  ux design
★  ew
★  yui
★  twitter bootstrap
★  bootstrap
★  jquery mobile
  dojo
  extjs
  selenium
  jquery tools
  kendo ui
  ajaxcontroltoolkit
  jquery
  ugm
  windows ui

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

Other search terms related to ui and their ratings are:
★★★★★ angular
★ long u sound
You have in mind a companion for ui and it is not yet here? Propose!



Google Trends

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