Colossal Mind Language Detector detects a user's preferred language. It parses the HTTP Accept-Language header and determines the most suitable language for the user from a list of supported languages. The detected language can fallback to a language associated with the user's country in case the Accept-Language header is not sent by the browser. The detected language can be stored in a cookie to avoid needing to detect the language again in subsequent requests.
libunibreak is an implementation of the line breaking and word breaking algorithms as described in Unicode Standard Annex 14 and Unicode Standard Annex 29. It is a superset of, and supersedes, liblinebreak. It is designed to be used in a generic text renderer. FBReader is one real-world example.
Easy I18N is a library that integrates GNU gettext with the JVM's internationalization facilities. Existing Java APIs (MessageFormat, DateFormat, Locale) are used to provide a much easier API for building and maintaining applications and Web apps. It includes the ability to use normal message strings in your code, use xgettext to auto-extract translatable strings, leverage the GNU gettext system and associated tools to manage translations, work with date, currency, and numeric input/output, supports thread-local Locales for Web apps (or global for apps), and more.