Genie: Fast and Robust Hierarchical Clustering R package genieclust version 1.3.0 CRAN Task View: Cluster (https://CRAN.R-project.org/view=Cluster) Genie is a robust hierarchical clustering algorithm (Gagolewski, Bartoszuk, Cena, 2016 <DOI:10.1016/j.ins.2016.05.003>). 'genieclust' is its faster, more capable implementation (Gagolewski, 2021 <DOI:10.1016/j.softx.2021.100722>). It enables clustering with respect to mutual reachability distances, allowing it to act as an alternative to 'HDBSCAN*' that can identify any number of clusters or their entire hierarchy. When combined with the 'deadwood' package, it can act as an outlier detector. Additional package features include the Gini and Bonferroni inequality indices, external cluster validity measures (e.g., the normalised clustering accuracy, the adjusted Rand index, the Fowlkes-Mallows index, and normalised mutual information), and internal cluster validity indices (e.g., the Calinski-Harabasz, Davies-Bouldin, Ball-Hall, Silhouette, and generalised Dunn indices). The 'Python' version of 'genieclust' is available via 'PyPI'. Software Imports: Rcpp, stats, utils, deadwood LinkingTo: Rcpp Suggests: datasets, Marek Gagolewski <marek@gagolewski.com> Comprehensive R Archive Network (CRAN) Marek Gagolewski [aut, cre, cph] (ORCID: <https://orcid.org/0000-0003-0637-6028>), Maciej Bartoszuk [ctb], Anna Cena [ctb], Peter M. Larsen [ctb] AGPL-3 2026-02-23 application/tgz https://CRAN.R-project.org/package=genieclust doi:10.32614/CRAN.package.genieclust