MirOS BSD is a free and open source operating system which started as a fork of OpenBSD 3.1 in August 2002. It was intended to maintain the security of OpenBSD with better support for European localisation. Since then it has also incorporated code from other free BSD descendants, including NetBSD, MicroBSD and FreeBSD. Code from MirOS BSD was also incorporated into ekkoBSD, and when ekkoBSD ceased to exist, artwork, code and developers ended up working on MirOS BSD for a while.
The GNU/Linux naming controversy is a controversy regarding whether computer operating systems that use GNU software and the Linux kernel should be referred to as "GNU/Linux" or "Linux" systems.
The GNU toolchain is a broad collection of programming tools produced by the GNU Project. These tools form a toolchain used for developing software applications and operating systems.
Free and Open source Software Developers' European Meeting (FOSDEM) is a non-commercial, volunteer-organized European event centered on free and open-source software development. It is aimed at developers and anyone interested in the free and open-source software movement. It aims to enable developers to meet and to promote the awareness and use of free and open-source software.
A runlevel is a mode of operation in the computer operating systems that implements Unix System V-style initialization. Conventionally, seven runlevels exist, numbered from zero to six. S is sometimes used as a synonym for one of the levels. Only one runlevel is executed on startup; run levels are not executed one after another.
In Unix-based computer operating systems, init is the first process started during booting of the operating system. Init is a daemon process that continues running until the system is shut down. It is the direct or indirect ancestor of all other processes and automatically adopts all orphaned processes. Init is started by the kernel during the booting process; a kernel panic will occur if the kernel is unable to start it, or it should die for any reason. Init is typically assigned process identifier 1.
Linux is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution (distro), which includes the kernel and supporting system software and libraries—many of which are provided by the GNU Project—to create a complete operating system, designed as a clone of Unix and released under the copyleft GPL license.
GNU variants are operating systems based upon the GNU operating system. According to the GNU project and others, these also include most operating systems using the Linux kernel and a few others using BSD-based kernels.
The Linux booting process involves multiple stages and is in many ways similar to the BSD and other Unix-style boot processes, from which it derives. Although the Linux booting process depends very much on the computer architecture, those architectures share similar stages and software components, including system startup, bootloader execution, loading and startup of a Linux kernel image, and execution of various startup scripts and daemons. Those are grouped into 4 steps: system startup, bootloader stage, kernel stage, and init process.
Illumos is a partly free and open-source Unix operating system. It has been developed since 2010 and based on OpenSolaris—after the discontinuation of that product by Oracle—and comprises of a kernel, device drivers, system libraries, and utility software for system administration. The core is now the base for many different open-sourced Illumos distributions, in a similar way in which the Linux kernel is used in different Linux distributions.
systemd is a software suite that provides an array of system components for Linux operating systems. The main aim is to unify service configuration and behavior across Linux distributions. Its primary component is a "system and service manager" — an init system used to bootstrap user space and manage user processes. It also provides replacements for various daemons and utilities, including device management, login management, network connection management, and event logging. The name systemd adheres to the Unix convention of naming daemons by appending the letter d. It also plays on the term "System D", which refers to a person's ability to adapt quickly and improvise to solve problems.
Alpine Linux is a Linux distribution designed to be small, simple, and secure. It uses musl, BusyBox, and OpenRC instead of the more commonly used glibc, GNU Core Utilities, and systemd. This makes Alpine one of few Linux distributions not to be based on the GNU Core Utilities.
OpenRC is a dependency-based init system for Unix-like computer operating systems. It was created by Roy Marples, a NetBSD developer who was also active in the Gentoo project. It became more broadly adopted as an init system outside of Gentoo following the decision by some Linux distributions not to adopt systemd.
musl is a C standard library intended for operating systems based on the Linux kernel, released under the MIT License. It was developed by Rich Felker to write a clean, efficient, and standards-conformant libc implementation.
PacBSD was an operating system based on Arch Linux, but used the FreeBSD kernel instead of the Linux kernel and the GNU userland. The PacBSD project began on an Arch Linux forum thread in April 2012. It aimed to provide an Arch-like user environment, utilizing the OpenRC init system, the pacman package manager, and rolling-release.
Devuan is a fork of the Debian Linux distribution that uses sysvinit, runit or OpenRC instead of systemd. Devuan aims to avoid "lock-in" by projects like systemd and aims to maintain compatibility with other init systems to avoid detaching Linux from other Unix systems.
Void Linux is an independent Linux distribution that uses the X Binary Package System (XBPS) package manager, which was designed and implemented from scratch, and the runit init system. Excluding binary kernel blobs, a base install is composed entirely of free software.
Hyperbola GNU/Linux-libre is an independent Linux distribution for the i686 and x86-64 architectures using the package-manager from Arch Linux and some patchsets from the Debian development though stopping using patchsets from Debian beyond the version Debian 12. It includes the GNU operating system components and the Linux-libre kernel instead of the generic Linux kernel. Hyperbola GNU/Linux-libre is listed by the Free Software Foundation as a completely free operating system, true to their Free System Distribution Guidelines.
