Understanding & setting up different input methods

I use [Trisquel](https://en.wikipedia.org/wiki/Trisquel) GNU/Linux 7.0 LTS with GNOME 3 [Flashback](https://wiki.gnome.org/Projects/GnomeFlashback) Environment. I heard about three different input methods viz. ibus, xim and uim. And it seems ibus is pre-installed on my system. $ cat trisquel_7.0_i686.iso.manifest | grep ibus gir1.2-ibus-1.0 1.5.5-1ubuntu3 ibus 1.5.5-1ubuntu3 ibus-gtk:i386 1.5.5-1ubuntu3 ibus-m17n 1.3.4-3ubuntu1 ibus-table 1.5.0.is.1.5.0.20130419-2 libibus-1.0-5:i386 1.5.5-1ubuntu3 libusb-0.1-4:i386 2:0.1.12-23.3ubuntu1 libusb-1.0-0:i386 2:1.0.17-1ubuntu2 libusbmuxd2 1.0.8-2ubuntu1 libustr-1.0-1:i386 1.0.4-3ubuntu2 While facing [this](https://unix.stackexchange.com/q/207025/66803) problem I learnt about installing uim and setting up with GTK_IM_MODULE="uim" at ~/.profile. Recently I removed uim and removed `GTK_IM_MODULE="uim" line from ~/.profile. But to overcome [this](https://bugs.launchpad.net/ubuntu/+source/gedit/+bug/367372) bug, I am planning to get rid of ibus` now. Without installing any extra input-method, (say fresh-install of Trisquel), echo $GTK_IM_MODULE outputs xim So, I'm confused because considering default input-method is ibus, then **why is $GTK_IM_MODULE saying xim?** **Also can I apt-get remove ibus? or I should install uim first and then remove ibus? Also I want to know which input method is currently working ibus or xim? And What is the right way to set the input method (i.e is it GTK_IM_MODULE="uim" to ~/.profile)?** Besides,I found one gsettings scheme: $ gsettings get org.gnome.desktop.interface gtk-im-module 'gtk-im-context-simple' Briefly/Broadly I need help to understand installing/removing and setting-up different input method: - How do I know which input-method is currently active? - How do I install and set-up different input-method? (should I remove another?)