BareMetal OS is an exokernel-based operating system developed in x86-64 assembly, focusing on raw compute and throughput without typical OS features like multitasking or complex abstractions. It's tailored towards efficiency and could support high-performance computing (HPC) applications. There's potential for a rewrite to ARM and RISC-V architectures as they standardize. The OS's design reflects a desire to minimize overhead and challenge conventional notions of operating systems. Discussions emphasize its practical applications, historical relevance, and the curiosity of returning to low-level programming. Many commenters also express nostalgia for simpler systems and contemplate current alternatives suitable for entry-level OS development.