I’m working with .NET localization lately, and this stuff helps me a lot.
Resex is translation friendly resource editor, which is created by Dimitris Papadimitriou.
It receives neutral culture .resx as an input, and it will produce a new .resx based on local culture that you select.
What makes it rocks is that you can edit local culture directly beside the base value (the value of neutral culture). Simple and effective.