Hoi, Yannf has added a category "language" to the categories that hold the words in a language. This gives you one list with all lists of words in a particular language. To make it really nice, he is adding links from one list of words in a language to the same list on a different wiktionary. This makes it possible to compare content between the different wiktionaries.
A category displays how many entries there are on a list; I have used this on the "nl:Hoofdpagina", the main page, to indicate how many languages we may have words in.
Thanks, GerardM