Story

Hi HN,

I have been working on an open source quantum computing SDK for the JVM called Quantum4J. I just launched the official site and wanted to share it here for feedback:

Website: https://quantum4j.com GitHub: https://github.com/quantum4j/quantum4j

What it is: A minimal quantum SDK written in Java Deterministic statevector simulator Strict OpenQASM 2.0 importer/exporter Pluggable backend design (example: IonQ REST API) JVM-first design so Java developers can build quantum workflows using familiar tooling

Why I built it Most quantum libraries are Python-centric and research-oriented; I wanted something that fits normal software engineering practices (builds, tests, CI/CD, Spring, etc).

Features Deterministic simulation (useful for testing + CI) QASM-based circuit interchange Clear, minimal API Real hardware backend example (IonQ) Examples included (Teleportation, Bell state, Grover, etc.)

Docs Full Javadoc published under /javadoc Examples included in the repo

Open to feedback

This started as a side project but it’s now getting more structure (examples, docs, hardware connector). I would love feedback from anyone doing quantum software, JVM work, hardware integration, or QASM tooling.

Thanks! Happy to answer questions.