>> except building compilers and OSes SBCL is written in Lisp, yes? Except the runtime, which is C + asm. I've heard people wrote some OSes in the past, like

>> except building compilers and OSes SBCL is written in Lisp, yes? Except the runtime, which is C + asm. I've heard people wrote some OSes in the past, like Genera. Or if you prefer recent attempt, try https://github.com/froggey/Mezzano https://github.com/froggey/Mezzano. Never tried it, though.