Eclipse Open VSX is a full-stack, vendor-neutral open-source registry for VS Code extensions, serving as an alternative to the Visual Studio Marketplace. The system comprises three main components: a Java/Spring Boot server that manages extension publishing, security scanning, rate limiting, download analytics, and trusted publishing via OIDC; a React/TypeScript web UI (MUI, TanStack Query) for browsing, searching, and administering extensions; and a Node.js CLI for publishing, verifying, and managing extensions. The server uses PostgreSQL with Flyway migrations, optional Elasticsearch for search, TimescaleDB for time-series download analytics, and Valkey/Redis for caching and rate limiting. Storage is abstracted over local filesystem, AWS S3, Azure Blob, and Google Cloud Storage. The architecture is a monolith with background job processing via JobRunr, and it exposes both a custom REST API and a VS Code Gallery-compatible API for seamless integration with VS Code and other editors.