Fcitx

Fcitx is a flexible input method platform for GNU/Linux. This page documents how to configure it for Malayalam Fcitx home page: https://fcitx-im.org/wiki/Fcitx

Installation
sudo apt-get install fcitx fcitx-m17n fcitx-libs fcitx-frontend-all

configuration
im-switch -s fcitx fcitx-configtool

Fom the configuration tool add your favorite input method. Make sure to uncheck "Show current language only" checkbox. Add as many input method you want. Close the configuration tool. From the same window you may want to configure the short cut for switching input methods as well.

Starting fcitx
run fcitx in command line or using task runner depending on your desktop environment.