Examples of apps or servers with hierarchial plugin architectures?

[odigity]

Operating systems and programming languages have hierarchial package systems, where package can declare dependencies on other packages.

What I'm looking for are examples of applications (like Slack or Chrome) or servers (like Postgres or Nginx) that have hierarchial plugin architectures. I can think of a thousand apps or servers with plugins, but every one that comes to mind is flat, not hierarchial, with no ability to specify dependencies.

[gtirloni]

Jenkins