Linux is a Unix-like, open source and community-developed operating system (OS) for computers, servers, mainframes, mobile devices and embedded devices. It is supported on almost every major computer platform, including x86, ARM and SPARC, making it one of the most widely supported operating systems.
How is the Linux operating system used?
Every version of the Linux OS manages hardware resources, launches and handles applications, and provides some form of user interface. The enormous community for developers and wide range of distributions means that a Linux version is available for almost any task, and Linux has penetrated many areas of computing.
For example, Linux has emerged as a popular OS for web servers such as Apache, as well as for network operations, scientific computing tasks that require huge compute clusters, running databases, desktop and endpoint computing, and running mobile devices with OS versions like Android.
The Linux OS can be found in many different settings, supporting many different use cases. Linux is used in the following ways:
- Server OS for web servers, database servers, file servers, email servers and any other type of shared server. Designed to support high-volume and multithreading applications, Linux is well-suited for all types of server applications.
- Desktop OS for personal productivity computing. Linux is an open source and freely available desktop environment for users who prefer it to commercial OSes.
- Headless server OS for systems that do not require a graphical user interface (GUI) or directly connected terminal and keyboard. Headless systems are often used for remotely managed networking server and other devices.
- Embedded device or appliance OS for systems that require limited computing function. Linux is used as an embedded OS for a variety of applications, including household appliances, automotive entertainment systems and network file system appliances.
- Network OS for routers, switches, domain name system servers, home networking devices and more. For example, Cisco offers a version of the Cisco Internetwork Operating System (IOS) that uses the Linux kernel.
- Software development OS for enterprise software development. Although many development tools have been ported to Windows or other OSes, Linux is home to some of the most widely used open source software development tools. For example, git for distributed source control; vim and emacs for source code editing; and compilers and interpreters for almost every programming language.
- Cloud OS for cloud instances. Major cloud computing providers offer access to cloud computing instances running Linux for cloud servers, desktops and other services.
Linux is highly configurable and depends on a modular design that enables users to customize their own versions of Linux. Depending on the application, Linux can be optimized for different purposes such as:
- networking performance;
- computation performance;
- deployment on specific hardware platforms; and
- deployment on systems with limited memory, storage or computing resources.
Users can choose different Linux distributions for specific applications or adapt a specific distribution to incorporate custom kernel configurations.
Linux distributions
Since its initial development, Linux has adopted the copyleft stipulations of the Free Software Foundation which originated the GNU GPL. The GPL says that anything taken for free and modified must be distributed for free. In practice, if Linux or other GNU-licensed components are developed or modified to create a new version of Linux, that new version must be distributed for free. This prevents a developer or other groups from profiting unfairly from the freely available work of others.
[email protected]:/mnt/c/WINDOWS/system32$This example shows the default command prompt in the Windows Subsystem for Linux. The prompt displays, from left to right, [email protected], and the full path of the current directory followed by the "$" symbol.
The pros and cons of using Linux
Some advantages of using Linux include:
- Open source software. The Linux kernel is released under the GNU GPL open source software license. Most distros include hundreds of applications, with many options in almost every category. Many distributions also include proprietary software, such as device drivers provided by manufacturers, to support their hardware.
- Licensing costs. Unlike Microsoft Windows or Apple macOS, Linux has no explicit licensing fees. While system support is available for a fee from many Linux vendors, the OS itself is free to copy and use. Some IT organizations have increased their savings by switching their server software from a commercial OS to Linux.
- Reliability. Linux is considered a reliable OS and is well-supported with security patches. Linux is also considered to be stable, meaning it can run in most circumstances. Linux also copes with errors when running software and unexpected input.
- Backward compatibility. Linux and other open source software tend to be updated frequently for security and functional patches, while retaining core functionality. Configurations and shell scripts are likely to work unchanged even when software updates are applied. Unlike commercial software vendors that roll out new versions of their OSes along with new ways to work, Linux and open source applications generally don't change their modes of operation with new releases.
- Many choices. Between the hundreds of available distributions, thousands of applications and almost infinite options for configuring, compiling and running Linux on almost any hardware platform, it is possible to optimize Linux for almost any application.
Some disadvantages of using Linux include:
- Lack of established standard. There is no standard version of Linux, which may be good for optimizing Linux for particular applications, but less so for deploying standardized server or desktop images. The wide range of options can complicate support as a result.
- Support costs. While an organization can acquire Linux freely without licensing fees, support is not free. Most enterprise Linux distributors like SUSE and Red Hat offer support contracts. Depending on the circumstances, these license fees can reduce savings significantly.
- Proprietary software. Desktop productivity software like Microsoft Office cannot be used on Linux desktops, and other proprietary software may be unavailable for Linux platforms.
- Unsupported hardware. While many hardware manufacturers make Linux device drivers available for their products, many do not.
- Steep learning curve. Many users struggle to learn to use the Linux desktop or Linux-based applications.
In some cases, the same Linux attribute can be either an advantage or disadvantage. For example, having many options for customizing the Linux OS is advantageous for manufacturers looking for an embedded OS, but it is a disadvantage for enterprises that want a desktop OS that can be used by a wide range of end users.
History of Linux
Linus Torvalds started working on Linux as a replacement to the Minix OS while at the University of Helsinki in Finland. Torvalds recognized the work done on the GNU Project in 1983, which intended to create a complete, Unix-compatible OS comprised entirely of free software, and noted the GNU as a model for distribution. However, the work on GNU had not been finished by the time Torvalds sought a Minix replacement, prompting him to develop an alternate OS kernel dubbed Linux -- a contraction of Linus' Unix -- and adopt the GNU GPL.
Torvalds released the Linux kernel in September 1991. A community of developers worked to integrate GNU components with Torvalds' kernel to create a complete, free OS known collectively as Linux. Torvalds continues to develop the Linux kernel and a vast developer community continues to create and integrate a wide range of components.
While Linux still lags Windows and macOS on the desktop, it continues to challenge the proprietary OS vendors on servers and embedded systems.
To find out more about the Linux experience, read how Windows systems administrators can gain new skills working with Linux.