Open Source Java Projects
Java is a general-purpose programming language and runtime platform used to build applications that run across operating systems and devices. Its strong type system, mature tooling, and broad ecosystem help teams develop server-side services, desktop software, mobile applications, and data-processing systems. Java is also used where long-term support, portability, and integration with established infrastructure are important.
Open source Java tools include frameworks, libraries, developer utilities, monitoring systems, and learning resources. When choosing one, consider its license, documentation, release history, maintenance activity, supported Java versions, security practices, and compatibility with your existing stack. Check whether its requirements fit your deployment environment and whether it can integrate with the services and build tools you already use. These resources are useful to beginners, application developers, platform teams, and organizations maintaining or modernizing Java systems.
16 repositories · updated September 15, 2026
AstronRPA: Open-Source Enterprise RPA Suite with AI Agent Integration
AstronRPA is an open-source, enterprise-grade Robotic Process Automation (RPA) desktop application. It features a low-code, no-code visual designer for building automation workflows across desktop software and web pages. Deeply integrated with AI agents, AstronRPA empowers broader business automation scenarios for both individuals and enterprises.
ACM-ICPC-Algorithms: A Comprehensive Collection for Competitive Programming
ACM-ICPC-Algorithms is a highly starred GitHub repository offering a vast collection of algorithms and data structures essential for competitive programming. It provides solutions in multiple languages, including C++, Java, and Python, making it an invaluable resource for participants of the ACM-ICPC and similar contests. With over 2200 stars and 1200 forks, this repository is a proven asset for mastering algorithmic challenges.
Awesome Java: A Curated List of Frameworks, Libraries, and Software
Awesome Java is a highly popular and comprehensive curated list of frameworks, libraries, and software for the Java programming language. With over 48,000 stars, it serves as an invaluable resource for developers seeking high-quality tools across various domains. This repository helps Java developers discover essential components for their projects, from architecture to web frameworks.
OpenDataLoader PDF: AI-Ready Data Extraction and Accessibility Automation
OpenDataLoader PDF is an open-source tool designed for extracting AI-ready data from PDFs and automating PDF accessibility. It provides structured Markdown, JSON with bounding boxes, and HTML outputs, ranking #1 in extraction accuracy benchmarks. The library also offers end-to-end auto-tagging to create screen-reader-ready Tagged PDFs, addressing critical accessibility compliance needs.
CompreFace: Free and Open-Source Face Recognition System with REST API
CompreFace is a leading free and open-source face recognition system that offers a robust REST API for various facial analysis tasks. It can be easily integrated into any system without requiring prior machine learning expertise, thanks to its Docker-based deployment. This powerful solution supports face recognition, detection, verification, and more, leveraging state-of-the-art methods like FaceNet and InsightFace.
java-sdk: The Official Java SDK for Model Context Protocol
The `java-sdk` is the official Java SDK for interacting with Model Context Protocol servers and clients. It provides a standardized interface for Java applications to communicate with AI models and tools, supporting both synchronous and asynchronous patterns. Developed in collaboration with Spring AI, it offers robust integration for building AI-powered applications.
HertzBeat: An AI-Powered Open Source Real-time Observability System
HertzBeat is an advanced, AI-powered open source observability system designed for real-time monitoring. It offers unified collection, centralized alerting, and intelligent management for a wide range of IT infrastructure, eliminating the need for agents. This comprehensive solution simplifies observability requirements for modern IT environments.
Quarkus: Supersonic Subatomic Java for Cloud-Native Applications
Quarkus is a leading Java framework designed for cloud-native and container-first environments. It enables developers to build high-performance, low-footprint applications with rapid startup times. By unifying imperative and reactive programming models, Quarkus offers a modern and efficient approach to Java development.
StarRocks: The Fastest Open Query Engine for Data Lakehouse Analytics
StarRocks is an open-source, high-performance query engine optimized for sub-second analytics across data lakehouses. It delivers best-in-class performance for multi-dimensional, real-time, and ad-hoc queries, making it a versatile solution for complex data analysis. This Linux Foundation project is engineered to provide speed and flexibility for various analytical scenarios.
kafka-ui: Manage and Monitor Apache Kafka Clusters
A web UI for monitoring and managing Apache Kafka clusters from one place. It helps Kafka operators and developers inspect brokers, topics, consumer groups, and messages, and configure cluster workflows through a browser.
Selenium: The Leading Framework for Browser Automation
Selenium is a comprehensive open-source project that provides tools and libraries for automating web browsers. It offers a platform and language-neutral coding interface, adhering to the W3C WebDriver specification, making it compatible with all major web browsers. This powerful framework is widely used for functional testing, regression testing, and general web automation.
Peergos: A P2P Secure File Storage, Social Network, and Application Protocol
Peergos is a peer-to-peer, secure platform designed for private file storage, social networking, and application hosting. It emphasizes user control over data, offering end-to-end encryption and fine-grained access control. Built on a decentralized architecture, Peergos aims to create a private web experience where users are protected from surveillance and data tracking.