replikativ / raster

Fast, functional numerical computing for Clojure/JVM.

ReactiveX / RxJava

RxJava – Reactive Extensions for the JVM – a library for composing asynchronous and event-based programs using observable sequences for the Java VM.

lysine-dev / okhttp

A meticulous HTTP client for the JVM, Android, and GraalVM.

lysine-dev / retrofit

A type-safe HTTP client for Android and the JVM

alibaba / arthas

Alibaba Java Diagnostic Tool Arthas/Alibaba Java诊断利器Arthas

openjdk / jdk

JDK main-line development https://openjdk.org/projects/jdk

itwanger / toBeBetterJavaer

一份通俗易懂、风趣幽默的Java学习指南，内容涵盖Java基础、Java并发编程、Java虚拟机、Java企业级开发、Java面试等核心知识点。学Java，就认准二哥的Java进阶之路😄

eclipse-vertx / vert.x

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

scala / scala

Scala 2 compiler and standard library. Scala 2 bugs at https://github.com/scala/bug; Scala 3 at https://github.com/scala/scala3

deeplearning4j / deeplearning4j

Suite of tools for deploying and training deep learning models using the JVM. Highlights include model import for keras, tensorflow, and onnx/pytorch, a modular and tiny c++ library for running math code and a java based math library on top of the core c++ library. Also includes samediff: a pytorch/tensorflow like library for running deep learn...

langchain4j / langchain4j

LangChain4j is an idiomatic, open-source Java library for building LLM-powered applications on the JVM. It offers a unified API over popular LLM providers and vector stores, and makes implementing tool calling (including MCP support), agents and RAG easy. It integrates seamlessly with enterprise Java frameworks like Quarkus and Spring Boot.

redpanda-data / redpanda

Redpanda is a streaming data platform for developers. Kafka API compatible. 10x faster. No ZooKeeper. No JVM!

playframework / playframework

The Community Maintained High Velocity Web Framework For Java and Scala.

doocs / jvm

🤗 JVM 底层原理最全知识总结

testcontainers / testcontainers-java

Testcontainers is a Java library that supports JUnit tests, providing lightweight, throwaway instances of common databases, Selenium web browsers, or anything else that can run in a Docker container.

dropwizard / metrics

:chart_with_upwards_trend: Capturing JVM- and application-level metrics. So you know what's going on.

Col-E / Recaf

The modern Java bytecode editor

junit-team / junit-framework

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

HaxeFoundation / haxe

Haxe - The Cross-Platform Toolkit

AsyncHttpClient / async-http-client

Asynchronous, non-blocking HTTP & WebSocket client for the JVM

lightbend / config

configuration library for JVM languages using HOCON files

btraceio / btrace

Production-safe dynamic tracing and diagnostics for Java applications—attach to live JVMs with no restart or recompilation.

apache / groovy

Apache Groovy: A powerful multi-faceted programming language for the JVM platform

reactor / reactor-core

Non-Blocking Reactive Foundation for the JVM

AlmasB / FXGL

Java / JavaFX / Kotlin Game Library (Engine)

SPLWare / esProc

esProc SPL is a JVM-based programming language designed for structured data computation, serving as both a data analysis tool and an embedded computing engine.

objectbox / objectbox-java

Database for Android and JVM - first and fast, lightweight on-device vector database

JetBrains / koog

Koog is a JVM (Java and Kotlin) framework for building predictable, fault-tolerant and enterprise-ready AI agents across all platforms – from backend services to Android and iOS, JVM, and even in-browser environments. Koog is based on our AI products expertise and provides proven solutions for complex LLM and AI problems

embabel / embabel-agent

Agent framework for the JVM. Pronounced Em-BAY-bel /ɛmˈbeɪbəl/

GradleUp / shadow

Gradle plugin for creating fat/uber JARs, transforming files, relocating packages, and optimizing with R8/ProGuard. The Gradle counterpart to Maven Shade Plugin.

apollographql / apollo-kotlin

:rocket:  A strongly-typed, caching GraphQL client for the JVM, Android, and Kotlin multiplatform.

jruby / jruby

JRuby, an implementation of Ruby on the JVM

Atmosphere / atmosphere

Portable AI agent runtime for the JVM. One @Agent class runs on Spring AI, LangChain4j, Anthropic, or 9 more behind one SPI. Token streaming, tool calls, human approvals, and governance over WebSocket, SSE, gRPC, or WebTransport/HTTP3. Speaks MCP, A2A, and AG-UI.

apache / logging-log4j2

Apache Log4j is a versatile, feature-rich, efficient logging API and backend for Java.

AxonIQ / AxonFramework

Framework for Evolutionary Message-Driven Microservices on the JVM

eclipse-openj9 / openj9

Eclipse OpenJ9: A Java Virtual Machine for OpenJDK that's optimized for small footprint, fast start-up, and high throughput. Builds on Eclipse OMR (https://github.com/eclipse/omr) and combines with the Extensions for OpenJDK for OpenJ9 repo.

AChep / keyguard-app

A password manager that supports Bitwarden platform and KeePass (KDBX) files. It autofills your logins, supports passkeys, works offline, and runs a Watchtower that finds leaked and reused passwords and other issues.

konsoletyper / teavm

Compiles Java bytecode to JavaScript, WebAssembly and C

assertj / assertj

Fluent testing assertions for Java and the JVM

cucumber / cucumber-jvm

Cucumber for the JVM

liftbridge-io / liftbridge

Kafka-style message streaming in Go. Built on NATS. Single binary, no JVM, no ZooKeeper.

com-lihaoyi / mill

A better build tool for Java, Scala and Kotlin: Simpler than Maven, easier than Gradle, with 3-7x faster dev workflows than other JVM build tools

flix / flix

The Flix Programming Language

mongodb / mongo-java-driver

The official MongoDB drivers for Java, Kotlin, and Scala

apache / logging-flume

Apache Flume is a distributed, reliable, and available service for efficiently collecting, aggregating, and moving large amounts of log-like data

cashapp / zipline

Run Kotlin/JS libraries in Kotlin/JVM and Kotlin/Native programs

prometheus / client_java

Prometheus instrumentation library for JVM applications

autonomousapps / dependency-analysis-gradle-plugin

Gradle plugin for JVM projects written in Java, Kotlin, Groovy, or Scala; and Android projects written in Java or Kotlin. Provides advice for managing dependencies and other applied plugins

jdbi / jdbi

The Jdbi library provides convenient, idiomatic access to relational databases in Java and other JVM technologies such as Kotlin, Clojure or Scala.

Foso / Ktorfit

HTTP client generator / KSP plugin for Kotlin Multiplatform (Android, iOS, Js, Jvm, Native, WasmJs)) using KSP and Ktor clients inspired by Retrofit https://foso.github.io/Ktorfit

gorules / zen

Open-source Business Rules Engine for your Rust, NodeJS, Python, Go, Java, C#, Kotlin (JVM), Kotlin (Android) and Swift (iOS) applications.

testng-team / testng

TestNG testing framework

openjdk / loom

https://openjdk.org/projects/loom

Discord4J / Discord4J

Discord4J is a fast, powerful, unopinionated, reactive library to enable quick and easy development of Discord bots for Java, Kotlin, and other JVM languages using the official Discord Bot API.

rakudo / rakudo

🦋 Rakudo – Raku on MoarVM, JVM, and JS

dzikoysk / reposilite

Lightweight and easy-to-use repository management software dedicated for the Maven-based artifacts in the JVM ecosystem 📦

codenameone / CodenameOne

Open-source framework for native apps from one Java codebase, with a custom-rendered UI you control across iOS, Android, desktop, web, and watches.

hcoles / pitest

State of the art mutation testing system for the JVM

datafaker-net / datafaker

Generating fake data for the JVM (Java, Kotlin, Groovy) has never been easier!

LuxLang / lux

The Lux Programming Language