All VyOS source code is hosted on GitHub under the VyOS organization which can be found here: https://github.com/vyos

Our code is split into several modules. VyOS is composed of multiple individual packages, some of them are forks of upstream packages and are periodically synced with upstream, so keeping the whole source under a single repository would be very inconvenient and slow. There is now an ongoing effort to consolidate all VyOS-specific framework/config packages into vyos-1x package, but the basic structure is going to stay the same, just with fewer and fewer packages while the base code is rewritten from Perl/BASH into Python using and XML based interface definition for the CLI.

The repository that contains all the ISO build scripts is: https://github.com/vyos/vyos-build

The README.md file will guide you to use the this top level repository.