We have the potential to have dozens of assemblies that will need to have multi-langugae support, and were wondering how this would best be managed.
1) Maintain one large resource assembly
2) Split it up by our component layers
3) Or a local resource per dll
4) Any better ideas
Also, how would you access these resources across potentially 20-25 apps
Use the established .NET localization model, i.e. satellite assemblies (one per language you support) for each localizable dll in your system.
Note that not all of your dlls may be localizable. Ideally only those that deal with the front end contain display text and other localizable content.
If you stick to the norm you'll benefit from the existing Visual Studio localization support (it builds the satellite assemblies for you) and other standard tools and processes that localization vendors are familiar with. If your project is very large, then there will be some amount of localization engineering involved, and it will be much better if you conform to the standard process.