# Reasons to Know Vim – It’s Similar to ed

There are many reasons to know Vim, but one of the more obscure ones is that it actually prepares you for the dreaded day when you have to use ed.

Today, I needed to see what went wrong when a buildpack was running on Heroku. For whatever reason, I couldn't for the life of me replicate the error on my local copy of the project, but when I tried to run it on Heroku, all it said was,

KeyError: '\xe4'

You're not meant to do this, obviously. The libraries Heroku downloads are intended to be kinda-sorta read only. You install them and then you use them. You don't change them. This is made clear when you discover that vim, nano, vi and friends are not recognised commands.
To my relief, though, ed was. Had I not been so comfortable with the ed command set (which Vim also uses, to a degree) I would not have been as relieved.