Java

FeignOpenFeign/feign

A Java HTTP client binder that simplifies writing declarative HTTP API clients using annotations.

flywayflyway/flyway

Flyway is a database migration tool that simplifies and automates schema evolution across multiple database instances.

JacksonFasterXML/jackson

A suite of high-performance Java data-processing tools for JSON and other formats, with streaming, databinding, and extensive module ecosystem.

Android-gif-drawablekoral--/android-gif-drawable

A library providing Views and Drawables for displaying and controlling animated GIFs on Android with native performance.

JsonPathjson-path/JsonPath

A Java DSL for reading, querying, and manipulating JSON documents using XPath-like expressions.

Apache JMeter (.2k)apache/jmeter

An open-source Java application for load testing and performance measurement of web services, databases, and various network protocols.

Cadence (.2k)uber/cadence

A distributed, scalable, and highly available orchestration engine for executing asynchronous long-running business logic.

flowableflowable/flowable-engine

A compact, highly efficient Java-based workflow and Business Process Management (BPM) platform with BPMN, CMMN, and DMN engines.

react-native-code-pushMicrosoft/react-native-code-push

A React Native module for CodePush enabling over-the-air updates of JavaScript and assets without app store resubmission.

okiosquare/okio

A modern I/O library for Android, Java, and Kotlin Multiplatform that complements java.io and java.nio.

async-profilerjvm-profiling-tools/async-profiler

A low overhead sampling profiler for Java that avoids safepoint bias and supports CPU, heap, and native memory profiling.

Checkstylecheckstyle/checkstyle

A development tool that helps programmers write Java code adhering to configurable coding standards and best practices.

JNAjava-native-access/jna

Java library providing easy access to native shared libraries without requiring JNI or native code.

Karate (.8k)karatelabs/karate

A unified open-source framework combining API testing, mocks, performance testing, and UI automation with a simple syntax.

Apache ShenYu (.7k)apache/shenyu

A Java-native, high-performance API gateway for microservices, offering service proxy, protocol conversion, and comprehensive API governance.

Apache Icebergapache/iceberg

A high-performance table format for huge analytic datasets, enabling multiple engines to safely work with the same tables simultaneously.

Delta Lakedelta-io/delta

An open-source storage framework that enables building a Lakehouse architecture with ACID transactions and scalable metadata handling.

Android Debug Databaseamitshekhariitbhu/Android-Debug-Database

A library for debugging Android databases and shared preferences directly in a browser.

Testcontainerstestcontainers/testcontainers-java

A Java library for JUnit tests that provides lightweight, throwaway Docker containers for databases, browsers, and other services.

docker-seleniumSeleniumHQ/docker-selenium

Docker images for running Selenium Grid with Chrome, Firefox, and Edge, enabling scalable browser automation.

Aeronreal-logic/Aeron

High-performance messaging system for reliable UDP unicast, UDP multicast, and IPC transport with predictable low latency.

Dropwizarddropwizard/dropwizard

A Java framework for building production-ready RESTful web services with integrated components.

Buckfacebook/buck

A fast build system for creating small, reusable modules across multiple platforms and languages.

Pentaho Data Integration (.3k)pentaho/pentaho-kettle

An open-source ETL (Extract, Transform, Load) tool for data integration and migration.

JavaCVbytedeco/javacv

Java interface to OpenCV, FFmpeg, and other computer vision libraries with utility classes for easier Java/Android integration.

BGAQRCode-Android RWbingoogolapple/BGAQRCode-Android

A customizable Android library for scanning and generating QR codes and barcodes using ZXing and ZBar.

SimianArmyNetflix/SimianArmy

A suite of tools for ensuring cloud resilience and operational efficiency, including Chaos Monkey for random instance failure testing.

Dropwizard Metricsdropwizard/metrics

A Java library for capturing JVM and application-level metrics to monitor system performance.

Extream Download Managersubhra74/xdm

A powerful download accelerator and video downloader that speeds up downloads up to 500% and saves videos from streaming sites.

MapStructmapstruct/mapstruct

A Java annotation processor for generating type-safe, high-performance bean mappers at compile time.

ClassySharkgoogle/android-classyshark

A standalone binary inspection tool for Android developers to browse executables and analyze bytecode.

h2oh2oai/h2o-3

An open-source, in-memory platform for distributed and scalable machine learning with support for a wide range of algorithms and big data technologies.

Leiningentechnomancy/leiningen

A build automation and dependency management tool for Clojure projects.

WireMockwiremock/wiremock

A flexible open-source tool for mocking HTTP services to create stable test and development environments.

WireMock (.1k)tomakehurst/wiremock

A flexible open-source tool for mocking HTTP services to create stable test and development environments.

nanohttpdNanoHttpd/nanohttpd

A lightweight, embeddable HTTP server library for Java applications, packaged as a single Java file.