I was a bit disappointed about how npm5's new feature to install from a local cache works. You must initially populate the cache from a registry (npmjs.com or w

I was a bit disappointed about how npm5's new feature to install from a local cache works. You must initially populate the cache from a registry (npmjs.com or whatever) because it caches by HTTP ETags (as I understood by experimenting); merely installing from local .tgz files results in an empty cache. But the reason I wanted the ability to install from a prepopulated cache in the first place was that I had to work at a customer behind corporate firewalls and a private registry (Artifactory), where each and every external package package has to be vetted individually for license and security issues. Which kind of defeats the purpose given the excessive transitive package dependencies in npm-land (300+ packages for a basic webpack/babel/react setup, 500+ packages for building Bootstrap from source; and these figures are still comparatively low). In exchange, you get a new cache directory layout with directories named after autogenerated hashes, and "npm cache list" isn't supported yet :( But I'm not complaining; npm has certainly made progress, though it's still relatively slow.