WordPress Meta Environment
The Meta Environment (WME) aims to make it easier to contribute to the network of official WordPress.org websites by automatically setting up a local development environment that is already provisioned with everything you need to get started on a patch. The environment will contain all of the open-source code that runs each supported site, as well as some sample data that mimics the production site.
WME is built on top of Varying Vagrant Vagrants (VVV), and works by provisioning the WordPress.org sites into an existing VVV installation. You can find a lot of documentation and resources for working with VVV on its homepage.
You can find more information about contributing to the official WordPress websites from the Meta team's handbook.
The goal is to eventually include all of the sites in the network.