If you’ve used an operating system with a command line interface, you’ve had Emacs available to you. It’s been around for decades (since Richard Stallman and Guy Steele wrote it in 1976), and its the other major text editor to stand behind in the Holy Text Editor Grail Wars. It’s not the easiest tool, but it’s definitely one of the most powerful. It has a steep learning curve, but it’s always there, ready for use. It’s had a long and storied history, but the version that most people wind up using is GNU Emacs, linked above. It’s richly featured, too—Emacs can handle almost any type of text that you throw at it, handle simple documents or complex code, or be customized with startup scripts that add features or tweak the interface and shortcuts to match your project or preference. Similarly, Emacs supports macro recording, tons of shortcuts (that you’ll have to learn to get really familiar with it), and has a ton of modules created by third parties to leverage the app for completely non-programming purposes, like project planning, calendaring, news reading, and word processing. When we say it’s powerful, we’re not kidding. In large part, its power comes from the fact that anyone can play with it and mold it into something new and useful for everyone.