`./lib` is for modules and components. There is no difference for us. You can share to client simple modules by adding a component.json file to that directory. And vice-versa by just exposing an index.js file. You can require('regexps') for example, from both server and client and work with same definitions without repeating code. So, `./lib` turns into a nice and sharable space. This is a construction from practices we've found on the way... component.io website is one of them.