German, American, or Other?
(All of these guys have svn commit privs on the core, as listed here)
Lundh: Other (Swedish)
Diederich: American (my great^8-grandfather was German)
Martelli: American/Other (originally Italian)
Kuchling: Other (Canadian)
Goodger: Other (Canadian)
Wolever: Other (Canadian or just in Canada?)
Forsberg: Other (Swedish)
Yoshida: I have no idea but I'm hoping this is a trick question
Niemeyer: Other (Brazilian)
Seutter: Other (Canadian)
Kaiser: German (?)
Schemenauer: Other (Canadian)
Wouters: Other (Dutch)
Petursson: American (probably, he speaks fluent Icelandic but I think he converted as a youth)
[highlight the text after the ':' to see the answer]
No doubt there are some errors in there so please leave corrections in the comments. Google isn't great for determining nationality and I didn't even google the answers I already "knew." Also, apologies to any Austrians who got lumped in with the Germans (a friend's grandmother at the age of 90 told her son she was Austrian after saying she was German for a lifetime. When confronted she replied "German, Austrian, whatever.")
Update (July 27, 2008) German ancestry is dominant in 17% of Americans or about 50 million people. You can be 1% German and have a German last name or 99% German and have a Spanish last name but if people mate randomly* the number of people with German last names would be at least as high as the number of people who self-report that they are mostly of German ancestry. There are 80 million Germans and somewhere near that number of Americans with German last names so this quiz becomes somewhat less surprising in hindsight.
* and mate randomly they do. The urge to mate is much stronger than any weak favoritism for ethnic continuity. In the US the idea that like-marries-like doesn't last for two generations (see "My Big Fat Greek Wedding"). And the idea is weakest in the majority (aka white people). Growing up I was amazed that the O'Dea kids down the street were 100% Irish. They weren't recent immigrants so the only thing in my mind was: wow, what are the odds?
If you want another anecdote, here's one: my father's father (who's last name I have, obviously) did not like the Pennsylvania Dutch ("Dutch" being the popular corruption of "Deutsch") . He was a 3rd generation New York German but he didn't care for the country bumpkin Pennsylvania Germans who got on a Westward boat 10+ generations before his own ancestors. His bias was entirely theoretical and limited to jokes and stereotypes. He didn't consider my mother (100% Dutchy) or any of her family as "Dutchy" because they were doctors, lawyers, businessmen, and engineers. He was encouraged to not bring it up and everyone else was reminded that he didn't really mean it. "Etlay itway opdray" is our family motto so this was rarely a problem.
NB, if you ever read a story about harsh race relations in America please take the last paragraph into account. My grandfather's rhetoric far exceeded reality. His words (accurately quoted!) would have been an indictment but were far different than his beliefs in practice.