Weka (Waikato Environment for Knowledge Analysis) is a popular suite of machine learning software written in Java, developed at the University of Waikato, New Zealand. It is free software available under the GNU General Public License. Weka features a comprehensive collection of data preprocessing and modeling techniques, making it ideal for developing new machine learning schemes. The software is also designed for data mining tasks, including data preprocessing, classification, regression, clustering, association rules, and visualization.Check it out at the official University of Waikato site: [Weka Machine Learning](https://www.cs.waikato.ac.nz)