Ruby-GetText for Ruby on Rails is the L10n library which works with Ruby on Rails 2.3.2 or later.

There are locale, gettext gems and other 3 libraries below which support rails:

locale_rails

• Auto-Detect the client locale
  • Detect candidate locales from supported locales by the application.
• Localized Routes
• Localized Action/Fragment cache
• Localized view template files
• I18n.t fallback to localized message candidates.

gettext_activerecord

• Validation messages translation
• Model translation
  • extract messages from models with the rake task.

gettext_rails

• Localization for some helpers.
• Works with other Rails I18n backend.
  • Note that gettext_rails is not the one of I18n backend.

These libraries are thread safe, and applications can use this library with your preferrable i18n backends which don't have above features.

(su)
$ gem install gettext_rails

• HOWTOs
  • HOWTO for Ruby on Rails
  • HOWTO for Rails Engines
  • HOWTO Migrate rails-2.1.x(gettext-1.93.0) to rails-2.3.2(gettext-2.0.0)
  • Ruby-GetText-Package HOWTO
  • HOWTO maintain po/mo files
  • HOWTO for CGI/ERB
  • HOWTO write your own message parsers
• Misc
  • Scope of the TextDomains
  • API reference
  • API reference(RDoc)
  • Tools
  • Movie(Japanese) by Ozawa Sakuro