The Smart Common Input Method platform (SCIM) is an input method (IM)
platform containing support for more than thirty languages (CJK and
many European languages) for POSIX-style operating systems including
Linux and BSD.
scim-bridge.el is a SCIM-Bridge client for Emacs. This program allows
users on-the-spot style input with SCIM. The input statuses are
individually kept for each buffer, and prefix-keys such as C-x and C-c
can be used even if SCIM is active. So you can input various languages
fast and comfortably by using it.