What are the best Java API repositories on GitHub?

The top-ranked Java API open source repositories include hapifhir/hapi-fhir, hub4j/github-api, TotalCross/totalcross, tracked and evaluated by community adoption, stars, and code commits.

How do I find trending Java API open source tools?

Browse this curated Java API directory to monitor real-time GitHub star velocity, latest code releases, and rising developer tools updated daily.

Are Java API GitHub repositories free and open source?

Most Java API projects listed here are distributed under open source licenses (such as MIT, Apache 2.0, or GPL). Always check individual project repositories for exact license terms.

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Java API GitHub Repositories (2026) · Open Source Tools

Discover the best Java API open source repositories on GitHub. Explore trending tools, live star counts, source code, and developer projects updated daily.

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3 matching projects · updated Nov 12, 2026 How we rank ↗

#1 TRENDING hapifhir/hapi-fhir Java 2014

🔥 HAPI FHIR - Java API for HL7 FHIR Clients and Servers

◇ apps ◇ fhir ◇ hapi-fhir ◇ healthcare

1.5K ↑ +6 today

2.4K

#2 TRENDING hub4j/github-api Java 2010

Java API for GitHub

◇ api ◇ client-library ◇ github ◇ github-api

783 ↑ +1 today

1.3K

#3 TRENDING TotalCross/totalcross Java 2020

TotalCross is a Software Development Kit that helps cross platform application development. Currently supported platforms are: Windows, Wince, Android, iOS, Linux and Linux ARM for embedded systems.

◇ c ◇ embedded-systems ◇ gui ◇ iot

43 ↑ +1 today

227

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