Building a mobile and web app with one codebase – dream come true. Read more about it here: A Glimpse Into The Future With React Native For Web  

Smashing published a wonderful overview of sending emails. Sending emails sounds simple, but there is a lot to consider (types of emails, spam, email clients your users use, CAN-SPAM Act compliance, etc…). An Introduction To Building And Sending HTML Email For Web Developers  

As a web developer, I get into the shell almost daily, but mostly using the same handful of commands. Whenever I need something outside of my daily routine, I have to google it. Here is a nice guide: http://code.tutsplus.com/articles/useful-nix-shell-commands-for-web-developers–cms-26161