“Kerla is a monolithic operating system kernel written from scratch in Rust which aims to be compatible with the Linux ABI, that is, it runs Linux binaries without any modifications.”
Matching the Linux ABI means existing binaries run on a new kernel. One developer got far enough to boot a Docker image as the root file system. The repo now says it is no longer maintained. Writing a kernel is the easy part. Keeping up with Linux’s syscall surface is the job that never ends.