Weka collects a general purpose and very popular wide set of ML algorithms implemented in Java and engineered specifically for DM [Weka] . It is a product of the University of Waikato, New Zealand and is released under GNU GPLv3- licensed for non-commercial purposes.
Weka has a package system to extend its functionality, with both official and unofficial packages available, which increases the number of implemented DM methods. It offers four options for DM: command-line interface (CLI), Explorer, Experimenter, and Knowledge flow. While Weka isn’t aimed specifically at Hadoop users and Big Data processing, it can be used with Hadoop thanks to a set of wrappers produced for the most recent versions of Weka3. At the moment, it still does not support Apache Spark, but only MapReduce. Clojure [Clojure] users can also leverage Weka, thanks to the Clj-ml library [Clj-ml]. Related to Weka, Massive Online Analysis (MOA) is also a popular open source framework written in Java for data stream mining, while scaling to more demanding larger-scale problems.
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