I want to calculate a unified diff comparing two documents. (The diff is to go in an email, and Wikipedia says unified diff is the best plain text diff format.)
var diff = Difference.DiffFiles(
before, FileType.Detect(before, null),
after, FileType.Detect(after, null),
options);
while (diff != null){
//DO What you like with the diff(s)
diff = diff.Next;
}