# JHDF5

> HDF5 for Java

**Wikidata**: [Q124795939](https://www.wikidata.org/wiki/Q124795939)  
**Source**: https://4ort.xyz/entity/jhdf5

## Summary
JDHF5 is a free Java library that lets programs read and write HDF5 files—an open standard for storing very large scientific datasets—under the permissive Apache 2.0 license. It is maintained at ETH Zurich and packaged for most major Linux distributions.

## Key Facts
- Distributed under the Apache Software License 2.0
- Source repository: https://sissource.ethz.ch/sispub/jhdf5
- Project page: https://unlimited.ethz.ch/pages/viewpage.action?pageId=92865195
- Packaged as “jhdf5” in AUR, Fedora, and Open-Hub; “libsis-jhdf5-java” in Debian/Ubuntu; “java-cisd-jhdf5” in GNU Guix
- Repology identifier: java:sis-jhdf5
- Instance of: free software (Wikidata class with 120 sitelinks)
- Reads and writes the Hierarchical Data Format version 5 (HDF5)

## FAQs
### Q: What does JHDF5 do?
A: It gives Java applications a native API to create, read, and modify HDF5 files without external native-code dependencies.

### Q: Is JHDF5 open source?
A: Yes; it is released under the Apache Software License 2.0, a permissive OSI-approved license.

### Q: How do I install JHDF5 on Ubuntu?
A: Run `apt install libsis-jhdf5-java`; the JAR is then available to your classpath.

### Q: Where is the project hosted?
A: ETH Zurich hosts documentation at unlimited.ethz.ch and the Git repository at sissource.ethz.ch/sispub/jhdf5.

## Why It Matters
Scientific workflows—from particle physics to climate modelling—generate terabytes of multidimensional data. HDF5 has become the de-facto container for such data because it offers self-describing, portable, and chunked storage that can be accessed in parallel. JHDF5 closes the gap between this binary format and the Java ecosystem, allowing desktop tools, web services, and big-data engines written in Java or Scala to ingest or produce HDF5 without calling C libraries. Because it is free software, research groups can embed it in grant-funded tools without legal friction, and Linux distributions can ship it in their science repositories, giving end-users one-command installation. In short, JHDF5 removes a language barrier and accelerates reproducible science.

## Notable For
- One of the few pure-Java solutions for full HDF5 read/write, eliminating native-code deployment headaches
- Carries an Apache 2.0 license, letting commercial and academic codebases embed it royalty-free
- Available out-of-the-box on Debian, Ubuntu, Fedora, Arch, and Guix, shortening setup time for Java-based lab software
- Maintained under the umbrella of ETH Zurich’s Scientific IT Services, giving it institutional backing