Vim is a highly configurable text editor for efficiently creating and changing any kind of text. It is included as "vi" with most UNIX systems and with Apple OS X. Vim is rock stable and is continuously being developed to become even better.
Atom is a free, open-source text editor for macOS, Linux, and Windows. It's modern, customizable, and hackable to the core—allowing you to customize it to your exact needs. It's also built with powerful features like autocompletion, file system browser, and more.