Sex Microkernel — 96× smaller than Linux. Hardware-enforced PKU isolation. Zero-copy PDX IPC. Lock-free. Wait-free. Every line pure Rust. This is what every OS should have been.
Traditional OSes fragment the world into isolated address spaces — a context switch, a TLB flush, a kernel crossing on every message. SexOS uses a single unified virtual address space for kernel, servers, and every user process. Everything sees everything. PKU enforces who may touch what.
One address space, sixteen hardware protection domains. Intel PKU —
Protection Keys for Userspace — enforces memory access rights at the CPU level.
No kernel involvement. Switching domains costs one instruction: WRPKRU.
Not a syscall. Not a context switch. One instruction.
WRPKRU in userspace — no syscall overhead
Linux IPC copies data between isolated address spaces — memcpy at every boundary. PDX (Protection Domain eXchange) passes raw pointers inside the single address space, flipping PKU keys atomically. The data never moves. Only the permission changes.
memcpy
pdx_call(slot, syscall, a0, a1, a2)
Every line is Rust. No C, no C++, no assembly beyond a handful of ISR stubs. The borrow checker eliminates use-after-free, buffer overflows, and data races at compile time — the kernel can't have memory safety bugs by construction. The entire image is 128 kilobytes. Linux is 30 megabytes.
Deep-dives into the kernel, live demos, architecture breakdowns. Follow the revolution from zero to replacement.
SexOS is an open project. If you know Rust, systems programming, or you just want to build the operating system of the future — we need you.
PKU domains, PDX IPC, work-stealing scheduler, ELF loader. Real OS work, pure Rust.
Display compositor, USB input, shell, window manager. User-space OS components.
Architecture docs, blog posts, tutorials. Help people understand what's possible.