Luit -- locale and ISO 2022 support for Unicode terminals - "Luit is integrated in XFree86 since version 4.2. Since then, Tomohiro Kubota has done some very useful work to make luit support irregular character sets (such as Shift-JIS and GBK), and made XTerm automatically invoke luit when needed. In case you need a standalone version, you can still download an obsolete version of luit."