H2O is an Open Source, Distributed, Fast & Scalable Machine Learning Platform: Deep Learning, Gradient Boosting (GBM) & XGBoost, Random Forest, Generalized Linear Modeling (GLM with Elastic Net), K-Means, PCA, Generalized Additive Models (GAM), RuleFit, Support Vector Machine (SVM), Stacked Ensembles, Automatic Machine Learning (AutoML), etc.
Add the TargetEncoding functionality to the Scala API: https://github.com/h2oai/h2o-3/blob/79feefba8470a24c3d011c4cb9105594c3230ebe/h2o-automl/src/main/java/ai/h2o/automl/targetencoding/TargetEncoder.java