Responsive by default - Blog | Andy Hume
http://blog.andyhume.net/responsive-by-default
Optimising for #One_Web, instead of specific browsers/devices/individuals, is an ideal that is a profound part of being a web developer. It has to be at the heart of everything you design and build. If not, you’re doomed to write code and support an ever increasing array of client platforms from whatever the browser landscape throws at you in the coming years. Good luck with that.