I am looking at using http://code.google.com/p/libphonenumber/ for a well-established project. Today the project does not use Google\'s libraries for JavaScript, favoring jQ
Here are two implementations of Google libphonenumber in JavaScript that have zero dependencies and are implemented in a single file. I've used Nathan Hammond's version without issue but it is not on NPM. Rui Marinho's version is on NPM.