What is the actual differences between I18n/L10n/G11n and specifically what does each mean for development?

I18n - Internationalization - Providing some kind of framework so that you can easily swap out strings, graphics, sounds and other resources and generally handling different conventions of communication.

L10n - Localization - The process of creating a bunch of strings, graphics, sounds etc. so that you can target a specific nationality, language or region.

G11n - Globalization - Doing both Internationalization and Localization steps :)

There are many methods and frameworks that support the 'strings' part of these processes and they usually involve using unicode. The other parts are usually handled by creating resource files with a bunch of graphics and sounds in them. Depending on the framework you use, the strings may be stored here too. I find Qt has an excellent system for handling strings for I18n.

I have an internationalized product. No translation has been done, but the strings are all externalized, so if we had a desire to ship the product localized for a specific country we could get the files translated, have the product tested, and ship it for use natively in that country.

For now the fully internationalized product is all english, but the coding is all done. If someone were to attempt to check in code that was not proper the reviewer could rightly reject it on the grounds that it is not internationalized, and would render the product unable to be fully localized.

But since no testing has been done then it really is not internationalized fully yet ...