For more detailed and information on this framework, you can clone the latest version at https://github.com/zeit/next.js. The installations and guides are clear and easy to follow.
This current version of NEXT looks really impressive. Although this has a lot of helpful methods and concepts, they are planning soon to release version 3.0 that focuses on HMR. HMR is a feature that is injected in specific module in active runtime. We can simply define it as a simple reload on module. On the other hand, compilation will be way faster.