How similar are Germany and Austria? How different are they?

[DavidB.]

Austria used to be almost entirely Catholic, while Germany has both a big Protestant and a big Catholic population, which has been relevant in its political history and in the formation of a national identity.

[DavidB.]

I think the comparison of Wallonia and France with Austria and Germany are quite interesting, mostly because it show the difference. Wallonia outside the occassional occupation have never been under France, and is in my opinion much more cultural German than French.

Apart from the German-speaking area in the east of Wallonia, this is simply untrue. Wallonia is culturally most similar to northern France.