The Baserock definitions format
The Baserock definitions format is a way of specifying components that need to be built, deployed and distributed in some way.
The Baserock reference definitions
We maintain a collection of definitions describing how to build lots of popular free software components. These are in a repository at git.baserock.org/baserock/baserock/definitions.
When modifying or defining your own Baserock systems, normally you will 'fork' this repository and use Git tooling to keep your changes in sync with ours.
It's also possible to write definitions completely independently of ours, if you want.