Antlink handles trees of repositories, where a meta-repository can point to other sub-repositories, some of which are checked out ("cloned") or not. Repositories stored at the same place can live in a "site", simplifying their discovery. The goal of antlink is to make groups of git (or other) repositories discoverable without requiring everyone check out everything.
Pre-built versions for RPM (Fedora, CentOS, REHL): see https://copr.fedorainfracloud.org/coprs/johnh/antlink/
See the antlink manual page for details.
Why use antlink? Why not use something else (git submodule, git subtree, git annex, Android repo, svn)? Good questions… the short answer is: none of them do things quite right. A much more detailed discussion is in the antlink manual page.