managed-systems is just a few custom lisp systems managed by me. It points to the systems using git's submodule feature. All the systems are forks from github, some with pull requests pending. :-)
To use, cd to the directory you cloned managed-systems into, and run ./install.sh
This will pull down the submodules, and write out ~/.config/common-lisp/source-registry.conf.d/23-managed-systems.conf
The file tells asdf2 to use the managed systems above quicklisp systems.