...Docker works well for packaging up development environments, but there are lots of tools that aren't tied to a particular project: awscli for managing your AWS account, ffmpeg for converting video, wget for downloading files, and so on. Whalebrew makes those things work with Docker, too. Whalebrew can run almost any CLI tool, but it isn't for everything (e.g. where commands must start instantly). It works particularly well for a Python app that requires C libraries, specific package versions, and other CLI tools that you don't want to clutter up your machine with. ...