I've seen people recommend npm over submodules. You can give it a git repo as a package and tag/commit as the version so it's not just for JavaScript repositori

I've seen people recommend npm over submodules. You can give it a git repo as a package and tag/commit as the version so it's not just for JavaScript repositories and also pulls the submodule's own npm dependencies. Although I don't know if you can put it wherever you want or it will always go to the node_modules directory.