H<sub>2</sub>O is an open-source, in-memory, distributed machine learning and predictive analytics platform developed by the company H2O.ai (previously 0xdata). The software uses a distributed architecture for parallel processing on standard hardware. It supports algorithms for large-scale data analysis and model deployment.
H<sub>2</sub>O is primarily used by data scientists and developers for statistical modeling and data-driven decision-making. The platform is designed to handle in-memory computations across a distributed computing environment. It offers implementations for numerous statistical and machine learning algorithms, which are accessible through various programming interfaces.
The software is released under the Apache License 2.0.
H<sub>2</sub>O provides a suite of supervised and unsupervised machine learning algorithms. Its core functions include:
The software can ingest data from various sources, including the Hadoop Distributed File System, Amazon S3, SQL databases, as well as local file systems. It operates natively on Apache Spark clusters through Sparkling Water. Proponents claim that improved performance is achieved compared to other analysis tools. The software is distributed free of charge, under a business model based on the development of individual applications and support.
H<sub>2</sub>O is primarily written in Java. It uses a distributed architecture that allows the platform to cluster nodes for parallel processing and in-memory storage of data and models.
Users interact with the H<sub>2</sub>O platform through several primary interfaces:
While the algorithm executes, approximate results are displayed, so that users can track the progress and intervene if needed.
The software project was initiated by the company 0xdata, which later changed its name to H2O.ai. The three Stanford professors Stephen P. Boyd, Robert Tibshirani and Trevor Hastie form a panel that advises H<sub>2</sub>O on scientific issues. Since its inception, H<sub>2</sub>O provides open-source machine learning libraries for enterprise use. The core H<sub>2</sub>O platform is often complemented by offerings from H2O.ai, such as H<sub>2</sub>O Driverless AI.
H<sub>2</sub>O is referenced in peer-reviewed literature regarding automated machine learning (AutoML). The platform has been categorized as a "Leader" and a "Strong Performer" in industry reports by Forrester Research. H<sub>2</sub>O (the open-source platform) and the associated commercial platform Driverless AI have been recurring winners of InfoWorld's most prestigious awards, including both the Best of Open Source Software ("Bossies") and the Technology of the Year awards.