For example, looking at http://www.vocabulink.com/link/29, the simplest way I have to tell the language at the moment is the title in the Latest Links list. I can't even tell what language it is from http://www.vocabulink.com/links?contains=to+learn or http://www.vocabulink.com/links?contains=lære.

Added for link pages. It's going to take some work to get it right for the link graph (search) page.