Hi guys, As for information, I would like to mention the existence of our SO3 operating system which support libc musl as its "libc" for user space applications. What is SO3? Smart Object Oriented Operating system is a compact, lightweight, full featured and extensible operating system particularly well-suited for embedded systems in general. SO3 is fully open source and GPLv2 compliant. https://smartobject.gitlab.io/so3 It currently works well (and maintained) in QEMU/vExpress environment as well as on Raspberry Pi 4 board. SO3 is great or academic environment (Operating System lecture for example) and industrial projects. Main features are : - Support of LVGL as graphical environment - Support of lwIP as networking stack - Support of libc MUSL - Support of MMU, user/kernel space, rootfs (currently FAT-32/MMC) - Support of device trees and is embedded in a U-boot FIT image (U-boot is required to boot SO3) SO3 is deeply based on Linux principles and build system, but it is tremendously simpler than Linux to grasp OS concepts and to make experiments very quick. And of course, it is very cool to use MUSL as a lightweight and powerful libc. Please note that, at the moment, LVGL can be tested in the emulated environment since we do not have any framebuffer/video driver for RPi4. We are also looking for passionate contributors who could help us in the evolution of SO3 (a lot of things remain to be improved/added :-)) During this Year, support for AArch64 and RISC-V is foreseen. Visit the site to keep in touch. If you have any interest in contributing or other, do not hesitate to ask :-) Cheers Daniel