Dumb-init vs Microcontainers: What are the differences?
What is Dumb-init? A minimal init system for Linux containers, by Yelp. dumb-init runs as PID 1, acting like a simple init system. It launches a single process and then proxies all received signals to a session rooted at that child process. Since your actual process is no longer PID 1, when it receives signals from dumb-init, the default signal handlers will be applied, and your process will behave as you would expect. If your process dies, dumb-init will also die, taking care to clean up any other processes that might still remain.
What is Microcontainers? Tiny, Portable Docker Containers. A Microcontainer contains only the OS libraries and language dependencies required to run an application and the application itself. Nothing more. Rather than starting with everything but the kitchen sink, start with the bare minimum and add dependencies on an as needed basis.
Dumb-init and Microcontainers can be primarily classified as "Container" tools.
Dumb-init and Microcontainers are both open source tools. It seems that Dumb-init with 3.8K GitHub stars and 211 forks on GitHub has more adoption than Microcontainers with 1.56K GitHub stars and 137 GitHub forks.