I was doing some testing of the implementation of the Jaro-Winkler comparator in Duke and I think there may be an issue but I'm not 100% sure.
I first computed the JW distance using the apache commons library. Then I did it with Duke. There are several cases where they don't match.
I found an online app (link below) that matches 1:1 with Apache commons, so that would lead me to think Duke is wrong - but who knows (maybe they are using the same library)?
Here are some examples where they differ:
GAGEL, MONTANEZ (AC=0.0, Duke=0.549)
KATHLEEN, LUCIA (AC=0.0, Duke=0.441)
HOOD, MONTANEZ (AC=0.458, Duke=0.583)
SILLE, ZENATNOM (AC=0.0, Duke=0.441)
HTINEK, ZENATNOM (AC=0.513, Duke=0.402)