- cl-gettext - cl-gettext is a binding the the GNU gettext internationalization library
- cl-i18n - cl-i18n is a GNU gettext-style internationalization library originally written by Leslie P
- cl-icu - cl-icu is a common lisp interface to the ICU internationalization library
- cl-l10n - cl-l10n is a localization library
- cl-locale - cl-locale is a simple i18n (internationalization) library for Common Lisp
- iso-3166-1 - iso-3166-1 is a list of ISO 3166-1 alpha-3 country codes
Unicode and character encoding: (main topic: character encoding)
- Babel - Babel is a character encoding/decoding library, not unlike GNU libiconv, but completely written in Common Lisp
- cl-unicode - CL-UNICODE provides Common Lisp implementations with knowledge about Unicode characters including their name, their general category, the scripts and blocks they belong to, their numerical value, and several other properties
- Cliconv - Cliconv is a simple FFI interface to the iconv library that lets Common Lisp programs translate byte sequences from/to different character encodings
- creole - creole is a library for converting a string between multibyte and unicode character encodings
- flexi-streams - FLEXI-STREAMS is a library which implements "virtual" bivalent streams that can be layered atop real binary/bivalent streams
- iconv - iconv is a iconv(man 3 iconv) Library