Secureblue is a security-hardened Linux distribution project built on Fedora Atomic (Silverblue, Kinoite, Sericea, Cosmic, IoT, and SecureCore variants). It produces bootable OCI container images via BlueBuild recipes and GitHub Actions CI, applying extensive hardening: kernel module blacklists, hardened kernel arguments, sysctl tuning, SELinux policy enforcement, systemd service lockdowns, setuid removal, secure boot with UKI signing, and DNS hardening. The runtime includes a comprehensive audit tool (audit_secureblue.py) that verifies security posture across ~30 categories with i18n support, plus interactive ujust commands for toggling hardening features.
Bazzite is a custom Fedora Atomic (Silverblue/Kinoite) operating system image optimized for gaming on desktops, handheld PCs (Steam Deck, ROG Ally, etc.), and HTPCs. It provides a SteamOS-like experience with pre-installed gaming tools (MangoHud, vkBasalt, OBS VkCapture), hardware support (OGC kernel, HDR/VRR, DisplayLink, per-device audio profiles), and a suite of system management utilities. The repository is not a traditional application but a build system for generating container images and ISOs. The architecture is container-native: images are built via Containerfile and GitHub Actions, with modular overlays for different variants (desktop, deck, nvidia) and desktop environments (GNOME, KDE). Key components include a justfile recipe library for user-facing configuration (ujust), systemd services, udev rules, RPM spec files with patches for upstream packages (BlueZ, UPower, Xwayland, MangoHud), and hardware detection scripts. The build process is fully automated via CI/CD, with image signing and attestation. The project is actively maintained with a large community and extensive hardware support.