GNU/Linux

GNU/Linux. Often referred to simply as Linux, it is a family of Unix-like operating systems based on the Linux kernel and the GNU userland. The system's development is one of the most prominent examples of free and open-source software collaboration, with contributions from thousands of individual developers and corporations like Red Hat, IBM, Intel, and Google. It powers a vast range of hardware, from embedded devices and supercomputers to personal computers and servers, with popular Linux distributions including Ubuntu, Fedora, and Debian.

History

The project's origins lie in the 1983 announcement of the GNU Project by Richard Stallman, aiming to create a complete Unix-compatible free software operating system. By the early 1990s, the project had developed many essential components, such as the GNU Compiler Collection and the GNU C Library, but lacked a working kernel. In 1991, Linus Torvalds, a student at the University of Helsinki, began developing a free kernel, which he later released under the GNU General Public License. The combination of Torvalds's kernel with the existing GNU system formed the basis of the first functional GNU/Linux systems. Early adopters and distributions, like Slackware and Debian, helped popularize the system throughout the 1990s, leading to significant commercial interest from companies like Red Hat and SUSE.

Design and philosophy

GNU/Linux is designed around the principles of modularity and the Unix philosophy, which emphasizes small, single-purpose programs that can be combined through pipes and other mechanisms. The system strictly separates the Linux kernel, which handles hardware and critical system resources, from the user space applications. This design is guided by a strong commitment to software freedom as defined by the Free Software Foundation, which advocates for users' rights to study, share, and modify the software they use. The pervasive use of plain text for configuration and data storage, along with comprehensive scripting capabilities, are hallmarks of this design ethos, inherited from its Unix ancestors like BSD.

Development and distribution

Development is highly decentralized, with the Linux kernel maintained by Torvalds and a team of key developers, including Greg Kroah-Hartman. Contributions are managed via the git version control system and flow through a hierarchy of subsystem maintainers. Separate projects, such as those for the GNOME and KDE Plasma desktop environments or the GNU Core Utilities, develop independently. These components are assembled into usable operating systems by Linux distribution maintainers like Canonical Ltd., the Debian Project, and openSUSE. Distributions provide customized kernels, package management systems like APT or RPM Package Manager, and installation programs, creating distinct variants such as Ubuntu, Arch Linux, and Fedora.

Usage and applications

The system dominates specific sectors due to its stability, security, and flexibility. It is the leading operating system on servers, powering much of the Internet infrastructure, including web servers running Apache HTTP Server and Nginx. It is the foundation of nearly all the world's supercomputers and is ubiquitous in embedded systems, from Android smartphones to routers and smart TVs. On the desktop, while having a smaller market share than Microsoft Windows or macOS, distributions like Linux Mint and Ubuntu offer a complete alternative for general computing. It is also pivotal in cloud computing platforms like Amazon Web Services and development environments at companies like Twitter and Netflix.

Licensing and legal aspects

The legal framework is defined primarily by copyleft licenses, most notably the GNU General Public License (GPL), which covers the Linux kernel and most GNU software. The GPL ensures that modified versions of the software remain free and under the same license, a principle central to the free software movement. Other components may use permissive licenses like the BSD licenses or the MIT License. This licensing model has led to notable legal discussions and cases, such as those involving the SCO Group and the enforcement of the GPL by organizations like the Software Freedom Law Center. The trademark on the name "Linux" is owned by Linus Torvalds and administered by the Linux Mark Institute.

Category:Free software operating systems Category:Unix-like operating systems