[ktpsns]

Yep, this is kind of npm but for browsers. But already the sheer size of npm shows how this is hardly possible: http://www.modulecounts.com/ -- I expect the npm repository to be at the size of two to three letters in gigabytes. This is quite large compared to the total hard disk cache of your browser (which also includes images, CSS, HTML, etc).

[achairapart]

Of course you don't need to download the whole repository as with npm. But just the links of the optimized distributable assets. In short, your /dist folder.

[robjan]

Since NPM is now the predominant way of distributing packages, they don't usually have a /dist folder so individual packages would again need to think about this. This was one of the reasons that bower is not really used anymore.