IBus is an Intelligent Input Bus. It is a new input framework for Linux OS. It provides full featured and user friendly input method user interface. It also may help developers to develop input method easily.
Mozc is a Japanese Input Method Editor (IME) designed for multi-platform such as Chromium OS, Windows, Mac and Linux.
ibus-mozc provides client part of the Mozc input method.
This open-source project originates from Google Japanese Input.