r18n-rails

https://github.com/r18n/r18n-rails

Out-of-box R18n support for Ruby on Rails. It is just a wrapper for R18n Rails API and R18n core libraries. R18n has nice Ruby-style syntax, filters, flexible locales, custom loaders, translation support for any classes, time and number localization, several user language support, agnostic core package with out-of-box support for Rails, Sinatra and desktop applications.