slim will build a micro-vm from a Dockerfile. Slim works by building and extracting a rootfs from a Dockerfile, and then merging that filesystem with a small minimal kernel that runs in RAM.
This results in a real VM that can boot instantly, while using very limited resources. If done properly, slim can allow you to design and build immutable unikernels for running services, or build tiny and embedded development environments.
A smarter Dockerfile linter that helps you build best practice Docker images. The linter is parsing the Dockerfile into an AST and performs rules on top of the AST. It is standing on the shoulders of ShellCheck to lint the Bash code inside RUN instructions.