Eclipse Open VSX is a vendor-neutral open-source alternative to the Visual Studio Marketplace. It provides a server application that manages VS Code extensions in a database, a web application similar to the VS Marketplace, and a command-line tool for publishing extensions. A public instance of the Registry is hosted by Eclipse (TBD), but more instances can be freely deployed in public or private places.
The primary purpose of this project is to provide a marketplace for VS Code extensions that can be used with Eclipse Theia and other IDEs. Another important goal is to allow self-hosting the Registry, e.g. within a company network. None of this is currently possible with the VS Marketplace, which is proprietary and may be accessed only from Visual Studio products.