General-purpose musl Linux distribution. dinit init, Oil packages. Boots to login in <1s on native virt (x86_64 KVM or aarch64 HVF).

Root model:

• Immutable rootfs — initramfs loads the complete OS into RAM from an erofs or squashfs image
• Persistent state — /home, package state, browser profiles, caches, and logs stay on disk under bcachefs-backed /state
• Desktop — a build profile layered on the immutable model, not a separate root-on-disk mode

scripts/boot-native.sh           # build + boot initramfs (QEMU)
system/backends/appliance/scripts/qemu.sh   # boot existing build

Platform support:

• x86_64 — main branch (primary target)
• aarch64 — arch/aarch64 branch — QEMU virt, Apple Silicon HVF
• riscv64 — arch/riscv64 branch — QEMU virt, OpenSBI
• Rockchip RK3566 — board/rk3566 branch — PINE64 Quartz64

GitHub releases publish live installer ISOs and compressed disk images for each edition and architecture:

Release asset names use:

alpenglow-VERSION-EDITION-ARCH.iso
alpenglow-VERSION-EDITION-ARCH.img.zst

Standard live ISOs use the terminal installer:

alpenglow-install-tui /run/alpenglow/alpenglow.img.zst /dev/sdX

Desktop live ISOs boot Alpenglowed and open the graphical installer against the same bundled image at /run/alpenglow/alpenglow.img.zst.

# Initramfs (diskless) mode — build + boot in QEMU
./scripts/boot-native.sh

# Custom kernel
KERNEL_BUILD=1 ./scripts/boot-native.sh

system/
  backends/
    appliance/          Primary profile (kernel configs, dinit services, scripts)
  kernelctl-zig/        Cgroup + kernel policy (Zig, 89KB static)
  netd-zig/             Network state daemon (Zig, zero deps)
  oil/                  Package manager (Rust, APK-compatible)
  kernel-modules/       Rust kernel modules (alpenglow_core, alpenglow_bootstat)
  init/                 Zig init (4.8KB static, initramfs fallback)
scripts/                Build, CI, benchmark scripts
docs/                   Architecture, build, install docs

Kernel configs live at system/backends/appliance/kernel/.

Release editions combine a userspace profile with a kernel profile:

Local release builds select the edition with ALPENGLOW_EDITION=fast|minimal|standard|desktop|desktop-full.

Alpenglow minimal (Zig init, 4.8KB) boots in 0.6s on x86_64 KVM. The standard build (dinit + toybox + getty) is 1.15s as a five-run median. Alpine matches boot speed but has a larger initramfs and uses more RAM. Both modes use the same toolchain — the difference is just initramfs contents.

Alpenglow standard and Alpenglowed Desktop rows are five-run medians on ultramarine with KVM, 4096MB RAM, 2 vCPU, and explicit initramfs boot. Alpenglowed Desktop (BUILD_PROFILE=desktop KERNEL_PROFILE=desktop GRAPHICAL=1 GRAPHICS_BACKEND=software QEMU_DISPLAY=none) reached serial login with Zig-backed kernel policy, netd, zram, and pressure services enabled. The measured desktop image had a 223MB rootfs, 66MB zstd initramfs, and 6.0MB kernel. This is down from the pre-trim desktop build at 689MB rootfs and 211MB initramfs. Xwayland, cage, wlroots, and the duplicate musl Mesa/LLVM stack are absent from the rootfs. This is not yet a graphical-session idle benchmark.

Fedora, Manjaro, and Ubuntu desktop rows are five-run medians from installed package-manager roots, not live ISOs or netinstall timings. They were built on ultramarine as minimal desktop images, copied to ext4 disks, and booted with the same QEMU shape used for Alpenglow comparison (q35, KVM, 4096MB RAM, 2 vCPU, virtio GPU, serial console). Boot time stops at systemd graphical.target; RAM is the last serial /proc/meminfo sample before that target. Fedora used GNOME/GDM from fedora:43 packages with a 2.2GB root and 2.4GB sparse image. Manjaro used XFCE/LightDM from manjarolinux/base:latest packages with a 2.0GB root and 2.2GB sparse image. Ubuntu used GNOME/GDM from ubuntu:24.04 packages with a 2.0GB root and 2.2GB sparse image.

Desktop runtime does not ship the system LLVM/Clang compiler toolchain; use the standard profile for that. COMPILER=inauguration selects the ../inauguration compiler track for compiler-capable images, but it does not remove lavapipe's Mesa LLVM dependency from the graphical runtime.

Alpenglow has one root model:

Immutable rootfs — boot from initramfs, load the OS into RAM, and keep state on a persistent bcachefs partition. /home, browser profiles, package state, logs, and caches bind from /state; the system image stays immutable. Target: appliance, workstation, edge, kiosk, and desktop builds.

Desktop — BUILD_PROFILE=desktop adds the graphical stack and Alpenglowed desktop environment on top of the immutable rootfs model. It is separate from standard; it is not a normal root-on-disk mode. The compositor model is Wayland + Smithay in Alpenglowed.

QEMU boot is verified. Real hardware boot has also been tested on Orange Pi 3B and Mac mini 2012.

See AGENTS.md for full milestone table and docs/ for architecture docs.