# java

Java diagnostic and troubleshooting tool

Arthas is Alibaba's open-source Java diagnostic tool that lets developers troubleshoot production issues without modifying code or restarting servers. It attaches to running JVM processes to inspect class loading, decompile classes, trace method invocations, monitor performance metrics, and view real-time stack traces. Supports JDK 6+ with both telnet and WebSocket interfaces for local and remote diagnostics across Linux, macOS, and Windows.

Versatile microservice framework for any protocol

Armeria is an open-source microservice framework from the creator of Netty at LINE Corporation that supports gRPC, Thrift, REST, and GraphQL on a single server and port. It provides built-in decorators for metrics, distributed tracing, load balancing, authentication, rate limiting, circuit breakers, and automatic retries. The framework integrates seamlessly with Spring Boot, Dropwizard, and Reactive Streams while serving automated API documentation with interactive request testing.

Self-hosted customer identity management with no per-user pricing

FusionAuth is a customer identity and access management platform that can be self-hosted or cloud-deployed with no per-user fees. It supports OAuth2, OIDC, SAML, passwordless login, social providers, MFA, and advanced threat detection. Features a drag-and-drop theme builder for login page customization and supports multi-tenant application architectures with unlimited users on the community edition.

Alibaba's Spring framework for building AI applications in Java

Spring AI Alibaba is Alibaba's open-source framework that brings AI capabilities to Java Spring Boot applications. It provides auto-configuration for AI model providers, RAG pipeline components, agent frameworks, and tool integration following Spring conventions. With 9,100 GitHub stars and 220+ contributors, it is the most mature AI framework for Java enterprise developers building production AI features.

Consumer-driven contract testing for APIs and microservices

Pact is the de-facto contract testing framework for HTTP APIs and event-driven systems across 12+ languages. It verifies that services can communicate correctly by testing API contracts from the consumer's perspective before deployment, catching breaking changes in microservice architectures. Maintained by Pact Foundation with 7,000+ combined GitHub stars across implementations. PactFlow offers a managed SaaS broker. Used widely in enterprise microservice teams to prevent integration failures.

MCP server for AI-powered reverse engineering

GhidraMCP is an MCP server that enables LLMs to autonomously perform reverse engineering tasks through NSA's Ghidra disassembly framework. It exposes binary analysis capabilities like decompilation, function listing, cross-references, and symbol analysis as MCP tools, letting AI assistants generate malware reports and analyze compiled binaries.

AWS managed AI code review for Java and Python

Amazon CodeGuru Reviewer is an AWS managed service that provides automated code analysis and recommendations on pull requests for Java and Python codebases. It integrates with GitHub, Bitbucket, and AWS CodeCommit, using machine learning trained on Amazon's internal code review practices to identify bugs, security vulnerabilities, and performance issues with IAM-based access control for enterprise governance.

AI documentation for legacy codebases

Kodesage is an AI platform designed for navigating and documenting legacy systems, consolidating knowledge from code, issue tickets, and wikis to generate function-level documentation. It creates AST-based code maps that help teams understand complex 20-year-old codebases in plain English, with on-premises and air-gapped deployment options for high-security enterprise environments.

Autonomous Java unit test generation in CI

Diffblue Cover is an AI-powered tool that autonomously writes and maintains Java unit tests within CI/CD pipelines, using a non-LLM AI approach specifically trained for test generation. It integrates as a GitHub Action and GitLab CI step, automatically generating tests on pull requests and updating existing suites when code changes, helping teams systematically reduce test debt without manual effort.

Code quality and security analysis platform

SonarQube is an open-source code quality and security platform with 9K+ GitHub stars that continuously inspects code for bugs, vulnerabilities, code smells, and security hotspots across 30+ programming languages. Enforces quality gates in CI/CD pipelines to prevent bad code from merging. Features include SAST scanning, duplicated code detection, technical debt tracking, and quality profiles. The industry standard for code quality management, used by 400K+ organizations worldwide.

Open-source identity and access management

Keycloak is an open-source IAM solution with 25K+ GitHub stars by Red Hat. Provides SSO, social login, LDAP/Active Directory federation, standard protocol support (OIDC, OAuth 2.0, SAML), fine-grained authorization, user federation, and admin console. Features identity brokering, multi-tenancy via realms, and client adapters for Java, JavaScript, and Node.js. Self-hosted with no per-user licensing, making it ideal for organizations needing full control over identity infrastructure.

Distributed search and analytics engine for all types of data.

Elasticsearch is the world's most popular open-source search and analytics engine, powering search experiences for companies like Wikipedia, GitHub, Netflix, and Uber. Built on Apache Lucene, it provides near-real-time search, structured and unstructured data analysis, and machine learning capabilities. Part of the Elastic Stack (ELK), it handles log analytics, application search, security analytics, and observability at scale. Supports vector search for AI/RAG applications.

Browser automation framework

The original browser automation framework with multi-language support for Java, Python, JavaScript, and C#. Drives end-to-end testing across all major browsers via the WebDriver protocol. Despite newer alternatives, Selenium remains the industry standard for large-scale automated browser testing, with the largest community and most extensive tooling ecosystem.

Workflow orchestration engine

Netflix-originated workflow orchestration platform with JSON and code-based workflow definitions, human-in-the-loop support, and AI agent orchestration capabilities. With 18k+ GitHub stars, Conductor handles complex distributed workflows at massive scale, offering built-in retry logic, event-driven triggers, and visual workflow monitoring for microservice coordination.

JetBrains database IDE

JetBrains' professional database IDE with intelligent SQL assistance, schema navigation, data editor, and admin tools for PostgreSQL, MySQL, Oracle, SQL Server, MongoDB, Redis, and more. Features context-aware completion, error detection, explain plan visualization, data export, and version control for schema changes. Part of JetBrains All Products pack or standalone. The premium choice for database development.

Universal database tool

DBeaver is a free, open-source universal database GUI and SQL client supporting 100+ engines including PostgreSQL, MySQL, Oracle, SQL Server, SQLite, MongoDB, Cassandra, and Redis. Offers a consistent cross-platform interface for schema browsing, visual query building, SQL execution, data editing, ER diagrams, and data migration between heterogeneous databases, all in a single Java-based desktop app.