A real operating system,
written entirely in Swift.
Most hobby kernels stop at “Hello from the kernel.” swift-os keeps going — a native Swift userland, an in-kernel TCP/IP stack, capability-based isolation, its own HTTP server, and a native Swift AI inference server. You can even try it in your browser.
swift-os answers real requests.
A pure-Swift, in-kernel TCP/IP stack drives virtio-net. /bin/httpd serves files and /bin/llmd serves a TinyStories transformer over HTTP on :8080 — both native Embedded Swift, running unprivileged at EL0. Boot it in your browser and hit it yourself.
[ ok ] swift-os kernel (Embedded Swift, signed) [ ok ] MMU enabled · EL1 · 256 MiB [ ok ] virtio-net up · DHCPv4 10.0.2.15/24 [ ok ] httpd listening on :8080 [ ok ] llmd ready · GET /health · POST /completion
:8080
Efficient, reliable minimalism — not another Unix.
A small trusted core, capability-based isolation, deterministic boot, and signed immutable images. swift-os removes legacy rather than emulating it.
Minimal Swift kernel
A freestanding Embedded Swift kernel — no Foundation, no stdlib, no GC. Value types and ~Copyable ownership at the metal.
Capability security
Authority is a capability you hold, not a uid you are. No ambient root==0 power; typed handles are landing now.
Native Swift userland
Real tools — a shell, id, ps, top, httpd, ssh — compiled as Embedded Swift, running unprivileged at EL0.
In-kernel networking
A pure-Swift TCP/IP stack over virtio-net: IPv4, DHCP, DNS, TCP/UDP — driving its own /bin/httpd.
AI inference, natively
/bin/llmd serves a TinyStories transformer over HTTP — POST /completion — written in Embedded Swift. The flagship app/AI-hosting profile, proven.
Immutable images
Boot a signed, read-only base.img; writes land in a tmpfs that vanishes on reboot. Reproducible by design.
A clear line between userland and kernel.
Swift tools run unprivileged at EL0. Every privileged action crosses a single, audited syscall boundary into the kernel at EL1, which owns the MMU, scheduler, network stack, and drivers.
See all diagramsWe tell you exactly what works today.
Experimental but real means no overclaiming. The status page carries the honesty so the rest of the site can be confident.