The program m17n-im-config provides a GUI for per-user configuration of
input methods of the m17n library (devel/m17n-lib and textproc/m17n-contrib).

The following methods are customisable at the moment: Unicode, Vietnamese,
Malayalam, Tibetan, Thai, Tamil, Japanese and Chinese.

     http://www.m17n.org/common/im-config/index.html