Dear Jean-Fred, Laura, Gergo, Brian and Nemo,

Thanks so much for your helpful answers to this question!

Nemo, your wikistats link is particularly useful, and suggests that about 15% of files on Wikimedia files may be stored outside of Commons, which is significant (3M out of 23M total).

I would be grateful for any URLs that would make it easy for us to test Media Viewer performance on the largest sites that have that practice of local hosting (e.g. English Wikipedia, who else?).

Laura, your URLs of local files on Wikinews is exactly what I’m looking for on other sites, thanks. A casual check suggests that these files open in Media Viewer, but their metadata doesn’t display, which could be due to Wikinews using a different template than Commons.

So my next question to the group is what you think can be done to encourage communities like Wikinews to consider adapting their templates to match the Commons more closely? Otherwise, their local images will not be as useful in Media Viewer.