This is a GNOME Shell extension for IBus. It is forked from the GJS UI implementation of IBus, and modified to work as an extension rather than a part of GNOME Shell javascript code.
This project aims to implement a new candidate panel with Shell Toolkit instead of GTK so that the candidate panel can be shown above GNOME Shell's native components (i.e. the IM notification).
This extension requires some new APIs which are not released yet. You need to install ibus from the git repository. See http://code.google.com/p/ibus/wiki/Install#Obtain_source_code for more detail.
To install this extension, just copy the whole directory to ~/.local/share/gnome-shell/extensions