HyPhy, or Hypothesis Testing using Phylogenies, is a sophisticated open-source software package designed for the analysis of genetic sequences, focusing on the inference of natural selection through advanced techniques in phylogenetics, molecular evolution, and machine learning. Launched in 2000, HyPhy has grown significantly, amassing over 10,000 registered users and featuring prominently in over 4,500 peer-reviewed publications.

HyPhy offers a powerful scripting language known as HBL (HyPhy Batch Language), enabling users to customize their analyses with ease, while also providing a range of pre-defined evolutionary models for convenience. The software supports various data types, including nucleotides, amino acids, and binary data, and allows for complex rate variation modeling and maximum likelihood methods. With features like ancestral sequence reconstruction, simulation capabilities, and modern web applications for result visualization, HyPhy serves as an essential tool for researchers aiming to explore evolutionary patterns and test hypotheses within genetic data. Whether you are a seasoned expert or a new user, HyPhy facilitates robust genetic analysis with its user-friendly and versatile approach.