wiki:i18n

If you want to see which translations are available or to if you want to help translating, please visit its page.

You can list all available languages by running:

opkg list | grep eglibc-locale-

And install the language of your choice (for example czech):

opkg install eglibc-locale-cs eglibc-localedata-cs-cs

After this, the Language Settings of Illume will offer Czech.

This will localize the Illume environment and will also set correct lang environment variable. If you wish to have translations for other applications, you need to install them again (presuming they are available):

This will install czech localisation for SHR phone applications, SHR Settings and TangoGps:

opkg install libframeworkd-phonegui-efl-locale-cs shr-settings-locale-cs tangogps-locale-cs

For localized terminal environment (ssh login) set lang variables set /etc/profile, example for Czech language:

export LANG=cs_CZ
export LC_ALL=cs_CZ

Taken from  SHR User Manual