This is a report about i18n and multilingual content implementation in Drupal, the current status, how it can be improved in the upcoming Drupal 4.7, and some long term strategy to get it fully integrated with Drupal core in the future.

Jose A Reyero wrote this report.  This is sitting on the Development Seed’s site because we are sponsoring the current improvements and wanted a place where we could put ‘everything’ so we could refer to it from Drupal.org to best share the details with anyone interested an more importantly get feedback and suggestion about how to make it better.  While a lot of the discussion is going to be happening on Drupal you can also comment here.

For people new to this discussion there is some very interesting work going on with multilingual support in Drupal.  Jose has worked on the i18n module, Rob Ellis wrote the TR module to handle some of his needs that were not met by the i18n module and Gerhard Killesreiter, Mike Gifford and Robert Douglas have all been extremely valuable contributions to discussing the ongoing needs.

There are a few concepts that, beyond the name of the current modules which are due more to development history and convenience -well, each module must have a name and the short it is the less you have to type- that have to be well understood and then make some distinction when we talk about i18n module or when we talk about i18n in general.

• Internationalization -i18n-, is the general support to run the application in different languages/countries/cultures. This have to be built in across the whole application.

• Localization -l10n-, is the specific translation and adaptation of the application to each language/country/culture.

• Multilingual -Sites and Content-, which is the ability to have the application running in several languages with one set up, serving content in multiple languages upon request.
Attending to this, we could state that Drupal -current stable version, 4.6.4- has good i18n support and l10n, but has limited multilingual support, that currently is provided by a contributed module which needs some patches to be applied to the core.

To read more... http://en.wikipedia.org/wiki/Internationalization.