The Heroku CLI is used to manage Heroku apps from the command line. It is built using oclif.
For more about Heroku see https://www.heroku.com/home
To get started see https://devcenter.heroku.com/start
This is the next generation Node-based Heroku CLI. The goals of this project were to make plugins more flexible, remove Ruby as a runtime dependency, and make the CLI faster.
It has identical functionality to the old Ruby CLI. Under the hood, it is a modular CLI made up of node.js plugins.
For more on developing plugins, read Developing CLI Plugins
For problems directly related to the CLI, add an issue on GitHub.
For other issues, submit a support ticket.