You can also make an alternative registry and add dependencies from that registry. That said, an alternative registry that enforces namespacing would not work,

You can also make an alternative registry and add dependencies from that registry. That said, an alternative registry that enforces namespacing would not work, just because of cargo's limitations on package names that prevent characters like / It could be done by making every "namespace" a different registry, and for those registries to allow packages with dependencies from other registries (something that crates.io doesn't allow, for a reasonably good reason). Would be quite verbose for the user though.