I used to think that Open Office was a Java application too, until I looked into it. Open Office is actually written in C++ (http://contributing.openoffice.org/programming.html), but it requires Java (I beleive for some components). I think that at one time it may have been written entirely in Java, because there was a huge rumor of it, or maybe its early performance led people to beleive that it was written in Java.

J.Ja