Translations
At this stage in its development, iD is using an extremely minimal, simple system for translations. This directory contains languages according to code (de: German, fr: French, etc).
To contribute:
If you're technically-minded, clone this repository and edit the necessary file, and you can preview your changes in-place if your system language is set. Check out the contributing guide for submitting changes.
If you aren't, you can still contribute! You'll still need a GitHub account, but you can just browse to your language's file here, click 'Edit', and edit each translated string.
Translating Strings
Let's look at an example line from en.js:
no_results: "Couldn't locate a place named '{name}'"
The word in brackets, {name}, should not be translated into a new
language: it's replaced with a place name when iD presents the text. So
a French translation would look like
no_results: "Impossible de localiser l'endroit nommé '{name}'"
License
Contributions to translations are under the same liberal license as iD itself, wtfpl.