Luet is a multi-platform Package Manager based off from containers - it uses Docker (and other tech) to sandbox your builds and generate packages from them. It has no dependencies and it is well suitable for "from scratch" environments. It can also version entire rootfs to enable delivery of OTA-alike updates.
Luet offers a simple [specfile format](https://luet-lab.github.io/docs/docs/concepts/specfile/) in YAML notation to define both packages and rootfs. As it is based on containers, it can be used to build seed stages for Linux From Scratch installations and it can build and track updates.
To install luet, you can grab a release on the [Release page](https://github.com/mudler/luet/releases) or compile it in your machine (requires Golang installed):
Luet is not feature-complete yet, it can build, install/uninstall/upgrade packages - but it doesn't support yet all the features you would normally expect from a Package Manager nowadays.