Side-by-side comparison

Tiny, MIT-licensed real-time kernel stewarded by AWS; the most widely deployed RTOS on microcontrollers.

Linux Foundation RTOS with devicetree, Kconfig and hundreds of boards; the fastest-growing vendor-neutral MCU OS.

Simple Makefile and Kconfig tool that generates small embedded Linux root filesystems, kernels and toolchains.

POSIX-compliant RTOS that scales from 8-bit to 64-bit MCUs; used by PX4 drones and Xiaomi's Vela OS.