there are many bare-metal tasking kernels to turn to — FreeRTOS, ThreadX (now Azure RTOS), RT-Thread, μC/OS, etc. By an academic definition, these are operating systems. However, compared to Linux, it’s more useful to think of these as a framework you use to write your bare-metal application inside.

Source: jaycarlson.net

I am not a she fyi

Source: nostrnests.com