OpenRC Init System

OpenRC is a dependency-based init system for Unix-like systems that works with the system-provided init program, normally sysvinit on Linux and rc on BSD. Originally developed as part of Gentoo Linux in 2007 by Roy Marples, OpenRC provides a lightweight alternative to systemd without sacrificing dependency resolution and parallel service startup. Key features: dependency-based startup where service dependencies declared in init scripts enable correct ordering with parallel initialization on multi-CPU systems. Pure POSIX shell implementation with minimal dependencies, consuming negligible memory and CPU, suitable for containers, embedded systems, and minimal installations. Runs on Linux, FreeBSD, NetBSD, OpenBSD, and GNU Hurd, making it one of the most portable init systems. Shell-based init scripts in /etc/init.d/ with standardized functions for start, stop, restart, status, and dependency declaration. Traditional sysvinit-style runlevels with additional named runlevels for custom configurations via rc-update. Service dependencies including need, use, after, before, and provide for flexible ordering. Global configuration via rc.conf and per-service configuration via /etc/conf.d/. Optional cgroup integration for process tracking and resource management on Linux. Optional supervision via s6, runit, or supervise-daemon for automatic restart. Works well inside Docker and LXC containers without PID 1 overhead. Used by default in Gentoo, Alpine Linux, Artix Linux, and available as alternative in Debian and Arch Linux.