R18n now has full compatibility with Rails I18n and add to Ruby on Rails: filters, i18n support for models, time formatters, nice syntax and out-of-box pluralizations and autodetect user locale. Also R18n has Sinatra, Merb and desktop plugins.

Completion Rake tasks by Tab with caching, package in Ubuntu on Rails PPA and sh tests :).

An agnostic and rich i18n tool R18n now has support for Sinatra.

R18n is an i18n tool. It isn’t a yet another Rails plug-in. R18n has a core gem and plugins for the Merb framework and desktop applications.
It can format numbers and time to the rules of the user locale. Translations are stored in YAML format with procedures and pluralization (“1 comment”, “5 comments”).
It has special support for countries with two official languages (exUSSR, China) and translation for commons words, like “OK”, “Cancel”, etc.