Ours is an open-source Mac application localized by volunteers. These volunteers will do their work on special localization builds of the software (with unstripped nibs), then send us the changes to integrate into the original xib and strings files.
The problem is that, while there is a way to integrate string changes without blowing away previous size changes, I can't see a way to integrate new string and size changes (as when we add or replace views).
The only way to do both that I can see is for localizers to work directly with the original xibs and send us diffs. That means they have to download the entire source code, not just a localizable version of the release, work in Xcode as well as IB, and either run the diff command themselves (per xib) or install and use Mercurial.
Is there any better way for a xib-based application?