Vim can be be pretty much installed anywhere that you could possibly ever code, making it incredibly useful to know. From your personal machine to SSH'ing into a production server, by knowing vim you can modify code wherever you are. Also offers a high level of customization for more advanced users.

What I like most is the amount of features it has, you can make complex edits with this editor. Allows you to use several shortcuts for editing. Another advantage is the amount of documentation, the community is quite broad, it is an editor available for any Unix-based OS (AIX, HP-UX), Linux (Debian, RHEL, Open Suse), etc.

Being able to manipulate text has never been more easy. With a few strokes of the keyboard, which I earned by being able to remember.