GNU/Linux, often called Linux, is a Unix-based and mostly POSIX-compliant computer kernel family built under the model of free and open-source software development and distribution, with many different flavors and versions (known as "distros"), based on the Linux kernel first released on October 5, 1991 by Linus Torvalds, and the userland of the GNU system, developed by Richard Stallman and the GNU Project. There are, however, systems that can be called "Linux distros", nothing less, nothing more, due to their lack of the GNU userland, such as Alpine (using musl as its C library and busybox as its core utility set). GNU/Linux has currently ca. 2% of the desktop market share, which is why many applications, mostly proprietary software, do not have GNU/Linux versions. Despite not being an optimal choice for gamers, a version of Linux called "Steam OS" made by Valve Corporation was a version of Linux compatible with many Windows PC games, mostly being games on the popular gaming platform , and Steam itself is available on most Linux distros.
Although GNU/Linux is for the most part free and open-source, some proprietary software is available for it, especially high-end software and development tools, such as JetBrains's tools, Autodesk Maya and Lightworks. In the rare case of an unrecoverable error, it handles it with a Kernel Panic, rather than a BSoD.
Linux is named "Linux" after its main developer, Linus Torvalds. Initially, when he was studying at the University of Helsinki, using an education-oriented UNIX-like system called "Minix" and developing his own monolithic kernel and operating system, he was going to name it Freax, a portmanteau of "freak", "free", and "x". The mascot and logo of the Linux kernel is the penguin Tux (shown right), chosen in a logo competition in 1996.
"Red Star OS", a North Korean operating system, is also Linux based; although its current version resembles Mac OSX rather than Linux, in which previous versions resembled Windows XP, then Windows 7. Using this system is considered illegal due to the enormous count of GNU GPL violations.
Desktop environments and window managers
A desktop environment is an implementation of the desktop metaphor, providing a graphical interface and programs that work under it. A window manager is the program that manages the windows for the GUI of the system - all desktop environments provide one, e.g. KDE uses KWin, GNOME uses Mutter (formerly Metacity), Xfce uses Xfwm, but there are also many standalone window managers for those who wish to customize their desktop further than most desktop environments allow.
Some Linux desktop environments and window managers include:
- Unity, the former default DE of Ubuntu, replaced by GNOME 3
- Cinnamon, the main DE of Linux Mint, available on most distros
- GNOME, the GNU Project's desktop environment
- KDE Plasma (formerly either KDE or Plasma), a Qt-based, thoroughly configurable DE available on all distros
- Xfce, a lightweight, modular, customizable, GNOME-independent GTK-based desktop environments for many *nix systems including GNU/Linux, Solaris and BSD-family systems
- LXDE, another lightweight and modular desktop environment that runs very well on old and deprecated hardware, using the Openbox window manager by default
- LXQt, a Qt-based fork of LXDE with more features
- MATE, a fork of GNOME 2 for those that miss its interface, kept up to date with modern technologies such as GTK+3
- Pantheon, the GNOME-based default DE of elementaryOS
- Fluxbox, an example of a standalone stacking window manager
- i3-gaps, an example of a standalone tiling window manager, a fork of the i3 WM with more features
Malware on LinuxDue to its relatively low market share and open-source/independent nature of the operating system, malware is rare and exploits are fixed rapidly. Most of the malware written for it is targeted towards websites or large business organizations due to the fact that it has a massive market share in servers, which makes GNU/Linux a lucrative target. They also rarely attack updated systems, as bugs being found are patched quickly, then added to update repos. Though there is not as much malware written for Linux, unlike Windows, cross-platform malware is becoming increasingly popular (since the common frameworks such as .NET Framework and Qt are cross-platform), and malware writers are now targeting Linux on the desktop more frequently. Android, which is a Linux kernel-based phone operating system, is also one of the most targeted platforms in the world on mobile for malware, because Android is the most common operating system on mobile devices. Some malware (such as Remaiten) may even run on other architectures (such as ARM or MIPS).
Debian is a unix-like operating system comprised of open-source software. It features it's own repositories, which is one of the biggest repositories of any Linux operating system, containing more than 51,000 programs. Many Unix-based operating systems like Mint and Ubuntu were based off of Debian.
No major breach has been made as of yet to Debian, however in 2008, a vulnerability was found in the random number generator of security keys, which only generated 32,767 different keys.
Linux Mint is a community-focused operating system that strives for a modern design and stability. It is open source and is bundled with open-source software. The current version is 19.2 "Tina".
Mint runs off of it's own repositories, which however, are outdated styles of repositories.
On 20 February 2016, the official Linux Mint website was breached by unknown hackers from Bulgaria, who briefly replaced download links for a version of Linux Mint with a modified version that contained malware. The hackers also breached the database of the website's user forum. After the attack Linux Mint was severely criticized as being a distribution that, unlike many others at the time, "just worked" and became popular with non-technical users, but at the expense of security, with some security updates to the underlying Ubuntu or Debian blacklisted from running due to compatibility issues.