oTranCe offers a ready to go and entirely web based translation platform to your project and your interpreters. The files you already translated can be imported easily and the present stage can be exported to language packages at any time. In case you are using a versioning system, updating your repository is just a mouse click.
All your interpreters will need is just a log in so they can start with working on the translations straight away. The administrator will be able to adjust very fine-grained rights and roles for your developers and interpreters.