You can hack it in a fair number of languages, but yeah, NPM's approach is pretty uncommon. E.g. in Java, you can use "Jar Jar Links" to recompile a lib into a

You can hack it in a fair number of languages, but yeah, NPM's approach is pretty uncommon. E.g. in Java, you can use "Jar Jar Links" to recompile a lib into a new namespace, which can allow multiple versions to coexist. NPM does make it transparent though, which is extremely convenient, and I can't name any other language that supports that. But that's not always an option. Bower exists for a reason - all that duplication / bloat is unacceptable for browsers to download. It can also mean hell for static initialization / mutable state, because there's no longer a single owner of the global resource.