There are a lot of books on this topic. You could always build a better mousetrap, of course. I'd be interested in a better mousetrap, OR find a new niche rat

There are a lot of books on this topic. You could always build a better mousetrap, of course. I'd be interested in a better mousetrap, OR find a new niche rather than yet another minix. How about a RTOS soft or hard your choice, or write it in a new or obscure language, or target it to a microcontroller (PIC32 ?) or target it to a softcore in a FPGA and develop the peripherals as you develop the drivers for them in parallel. How about an OS designed from the start specifically to live inside virtual containers, to optimize its performance both boot up, drivers, and shutdown while virtualized? Has anyone ever written a power-aware OS and what would that mean? I don't mean a mere ACPI driver but something written from the bottom up to minimize watt/hrs burned by the OS rather than pure speed as sole criteria. That would be an interesting "hook" even if the rest of the book is fairly traditional. How about an OS that is some kind of kissing cousin / lovechild of a java virtual machine? Where the native executable format is a jar file, where the whole thing runs in the JVM, for no reason other than I'm daydreaming right now? (Edited to add, I like retrocomputing so how about a C re-implementation of a classic OS, like maybe PDP-8 OS/8? Small simple yet capable, make it as compatible as you can. Or TRSDOS, or port Microware OS-9 and/or Nitros9 to ... something, maybe intel PC I donno) (Edited to add, strange filesystem idea #2515 how about a cloud / nosql database as your native root filesystem? What a strange idea, yet interesting.)