Design patterns implemented in Java

Free and Open Source, Distributed, RESTful Search Engine

Google core libraries for Java

A browser automation framework and ecosystem.

OpenAPI Generator allows generation of API client libraries (SDK generation), server stubs, documentation and configuration automatically given an OpenAPI Spec (v2, v3)

Redisson - Valkey & Redis Java client. Real-Time Data Platform. Sync/Async/RxJava/Reactive API. Over 50 Valkey and Redis based Java objects and services: Set, Multimap, SortedSet, Map, List, Queue,…

GraalVM compiles applications into native executables that start instantly, scale fast, and use fewer compute resources 🚀

光 HikariCP・A solid, high-performance, JDBC connection pool at last.

Zipkin is a distributed tracing system

Logstash - transport and process your logs, events, or other data

Vert.x is a tool-kit for building reactive applications on the JVM

Very spicy additions to the Java programming language.

A Java API for generating .java source files.

A barebones WebSocket client and server implementation written in 100% Java.

Spinnaker is an open source, multi-cloud continuous delivery platform for releasing software changes with high velocity and confidence.

Java Native Access

A programmer-oriented testing framework for Java — ⚠️ maintenance mode

Examples and server integrations for generating the Swagger API Specification, which enables easy access to your REST API

A tool for mocking HTTP services

Java DSL for easy testing of REST services

✅ The programmer-friendly testing framework for Java and the JVM

Hazelcast is a unified real-time data platform combining stream processing with a fast data store, allowing customers to act instantly on data-in-motion for real-time insights.

Asynchronous Http and WebSocket Client library for Java

Generate Java types from JSON or JSON Schema and annotate those types for data-binding with Jackson, Gson, etc

Simple OAuth library for Java

Allure Report is a flexible, lightweight multi-language test reporting tool. It provides clear graphical reports and allows everyone involved in the development process to extract the maximum of in…

Apache Ignite

H2 is an embeddable RDBMS written in Java.

The official AWS SDK for Java 1.x (In Maintenance Mode, End-of-Life on 12/31/2025). The AWS SDK for Java 2.x is available here: https://github.com/aws/aws-sdk-java-v2/

High performance non-blocking webserver