Spring Boot helps you to create Spring-powered, production-grade applications and services with absolute minimum fuss.

Spring Framework

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

a fast, scalable, multi-language and extensible build system

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

Graphs for Everyone

Open source alternative to Auth0 / Firebase Auth / AWS Cognito

🏗 Build container images for your Java applications.

Generate diagrams from textual description

Your Cheat Sheet For Android Interview - Android Interview Questions and Answers

Flyway by Redgate • Database Migrations Made Easy.

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.

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

Micronaut Application Framework

Keep your code spotless

MapDB provides concurrent Maps, Sets and Queues backed by disk storage or off-heap-memory. It is a fast and easy to use embedded Java database engine.

🔬 Java Code Coverage Library

Roadmap to becoming a Java developer in 2026

A tool to help eliminate NullPointerExceptions (NPEs) in your Java code with low build-time overhead

Bundletool is a command-line tool to manipulate Android App Bundles

Library for OpenAPI 3 with spring-boot

requery - modern SQL based query & persistence for Java / Kotlin / Android

Confluent Schema Registry for Kafka

The open source, cloud native tool for API Mocking and Testing. Microcks is a Cloud Native Computing Foundation sandbox project 🚀

Collection of JUnit example projects

The most advanced ORM of JVM, for both java & kotlin

Spring Integration for GraphQL

Transactional schema-less embedded database used by JetBrains YouTrack and JetBrains Hub.