Globalize on Ruby-On-Rails

The Globalize is an internationalization and localization plugin for Rails application.

• Translates both db content and view text.
• Supports automatic selection of an alternate, localized template for each view.
• Built-in localization and translation of strftime, numbers, and currency formats.
• Supports pluralization.
• All based on three automatically migrated database tables.

It is the best solution to support multi-languages for your rails application.
The globalization wiki is not yet complete. But I think the "Get Started" part is fair enough to help you out making your globalized application, it provides very helpful external links.

1. Sven’s Globalize Writeup – has many times been refered to as “the best documentation available for Globalize” .
   
2. Example Application – takes you step by step through the process of creating a Globalized example application.
3. Unit-tested Example – a walkthrough using a test-driven approach by Josh Harvey.