Weka is another New Zealand open source project to come out of a research environment. In this case Waikato University’s Machine Learning Group. It is a world-class tool for exploring and extracting information from data. And a hugely popular one at that, with some 20-30,000 downloads per month from SourceForge over recent years. According to one nomination from Israel, Weka is the de facto standard in the machine learning community, used not because it is free, but because it is the best.