Linus Torvalds was a student in Helsinki, Finland, in 1991, when he started a project: writing his own operating system kernel. It wasn’t long before this became known as the Linux kernel.
He also collected together and developed the other essential ingredients required to construct an entire operating system with his kernel at the center.
It has been subsequently ported to an astoundingly long list of other hardware platforms, from tiny embedded appliances to the world’s largest supercomputers.
In 1992, Linux was re-licensed using the General Public License (GPL) by GNU (a project of the Free Software Foundation or FSF, which promotes freely available software), which made it possible to build a worldwide community of developers. By combining the kernel with other system components from the GNU project, numerous other developers created complete systems called Linux distributions in the mid-90’s.
Since its inception in 1991, Linux has grown to become a major force in computing – powering everything from the New York Stock Exchange to mobile phones, supercomputers, and consumer devices.
It is an open-source computer operating system, initially developed on and for Intel x86-based personal computers.
Home For Linux Creator
It is the world’s largest and most pervasive open-source software project in history. The Linux Foundation is home to Linux creator Linus Torvalds and leads maintainer Greg Kroah-Hartman.
And provides a neutral home where its kernel development can be protected and accelerated for years to come. The success of Linux has catalyzed growth in the open-source community.
Today, it powers more than half of the servers on the Internet, the majority of smartphones (via the Android system, which is built on top of Linux), and all of the world’s most powerful supercomputers.
Demonstrating the commercial efficacy of open source and inspiring countless new projects across all industries and levels of the technology stack.
The Linux distributions created in the mid-90s provided the basis for fully free (in the sense of freedom, not zero cost) computing and became a driving force in the open-source software movement.
In 1998, major companies like IBM and Oracle announced their support for the Linux platform and began major development efforts as well.
The Linux community is a far-reaching ecosystem consisting of developers, system administrators, users, and vendors who use many different forums to connect with one another. Among the most popular are:
- Internet Relay Chat (IRC) software (such as WeeChat, HexChat, Pidgin, and XChat)
- Online communities and discussion boards including Linux User Group (both local and public)
- Many collaborative projects hosted on services such as GitHub
- Newsgroup and mailing list including the Linux kernel mailing list
- Community events like Hackathons, Install Fests, Open Source Summits, and Embedded Linux Conferences
A portal to one of the most powerful online user communities can be found at https://www.linux.com. This site is hosted by The Linux Foundation and serves over one million unique visitors every month. It has active sections on:
- Community discussion threads
- Free tutorials and user tips
Today’s Linux Foundation’s work extends far beyond Linux, fostering innovation at every layer of the software stack. The Linux Foundation is the umbrella organization for many critical open-source projects that power corporations today, spanning all industry sectors:
- Big data and analytics: ODPi, R Consortium
- Networking: OpenDaylight, ONAP, OPNFV
- Embedded: Dronecode, Zephyr
- Web Tools: Js Foundation, Node.js
- Cloud computing: Cloud Foundry, Cloud Native Computing Foundation, Open Container Initiative
- Automotive: Automotive Grade Linux
- BlockChain: Hyerledger
The families and representative distributions are:
For other distributions click here
Sometimes that effort creates a whole new distribution. Sometimes, that effort will leverage an existing distribution to expand the members of an existing family.
Red Hat Family
Red Hat Enterprise Linux (RHEL) heads the family that includes CentOS, Fedora, and Oracle.
Fedora has a close relationship with RHEL and contains significantly more software than Red Hat’s enterprise version.
One reason for this is that a diverse community is involved in building Fedora, with many contributors who do not work for Red Hat. Furthermore, it is used as a testing platform for future RHEL releases.
CentOS is often used for activities, demos, and labs because it is available at no cost to the end-user and has a much longer release cycle than Fedora (which releases a new version every six months or so).
The basic version of CentOS is also virtually identical to RHEL, the most popular Linux distribution in enterprise environments.
Key Facts About RHEL
Fedora serves as an upstream testing platform for RHEL.
CentOS is a close clone of RHEL, while Oracle is mostly a copy with some changes (in fact, CentOS has been part of Red Hat since 2014).
A heavily patched version 3.10 kernel is used in RHEL/CentOS 7, while version 4.18 is used in RHEL/CentOS 8.
It supports hardware platforms such as Intel x86, Arm, Itanium, PowerPC, and IBM System z.
It uses the yum and dnf RPM-based yum package managers to install, update, and remove packages in the system.
RHEL is widely used by enterprises which host their own systems.
SUSE Family : Linux
The relationship between SUSE (SUSE Linux Enterprise Server (SLES) ) and OpenSUSE is similar to the one described between RHEL, CentOS, and Fedora.
We use openSUSE as the reference distribution for the SUSE family, as it is available to end users at no cost.
Because the two products are extremely similar, the material that covers openSUSE can typically be applied to SLES with few problems.
Key Facts About SUSE
SUSE Linux Enterprise Server (SLES) is upstream for openSUSE.
It uses the RPM-based zypper package manager to install, update, and remove packages in the system.
It includes the YaST (Yet Another Setup Tool) application for system administration purposes.
SLES is widely used in retail and many other sectors.
The Debian distribution is upstream for several other distributions, including Ubuntu. In turn, Ubuntu is upstream for Mint and a number of other distributions.
It is commonly used on both servers and desktop computers. Debian is a pure open source community project (not owned by any corporation) and has a strong focus on stability.
Ubuntu aims at providing a good compromise between long-term stability and ease of use.
Since Ubuntu gets most of its packages from Debian’s stable branch, it also has access to a very large software repository.
Key Facts About Debian
The Debian family is upstream for Ubuntu, and Ubuntu is upstream for Mint and others.
It uses the DPKG-based APT package manager (using apt, apt-get, apt-cache, etc) to install, update, and remove packages in the system.
Ubuntu has been widely used for cloud deployments.
While Ubuntu is built on top of Debian and is GNOME-based under the hood, it differs visually from the interface on standard Debian, as well as other distributions.
Terminology of Linux
When you start exploring, you will soon come across some terms which may be unfamiliar, such as distribution, boot loader, desktop environment, service, file system windows system, command line, etc.
Before we proceed further, let’s stop and take a look at some basic terminology to help you get up to speed.
The kernel is considered the brain of the operating system. It controls the hardware and makes the hardware interact with the applications.
The most recent kernel, along with past kernels, can be found at the kernel.org web site.
The boot loader, as the name implies, is a program that boots the operating system.
Two examples of a boot loader are GRUB and ISOLINUX.
Desktop Environment and X Windows System
The desktop environment is a graphical user interface on top of the operating system. GNOME, KDE, Xfce and Flux box are some examples of the desktop environment.
The X Window System provides the standard toolkit and protocol to build graphical user interfaces on nearly all Linux systems.
A filesystem is a method for storing and organizing files in it. Some examples of filesystems are ext3, ext4, FAT, XFS and Btrfs.
CLI and Shell
The command line is an interface for typing commands on top of the operating system.
The Shell is the command line interpreter that interprets the command line input and instructs the operating system to perform any necessary tasks and commands.
For example, bash, tcsh and zsh.
A service is a program that runs as a background process. Some examples of the service are httpd, nfsd, ntpd, ftpd and named.
Services Associated With Linux Distributions
The vast variety of distributions are designed to cater to many different audiences and organizations, according to their specific needs and tastes.
However, large organizations, such as companies and governmental institutions, and other entities, tend to choose the major commercially supported distributions from Red Hat, SUSE, and Canonical (Ubuntu).
CentOS is a popular free alternative to Red Hat Enterprise Linux (RHEL) and is often used by organizations that are comfortable operating without paid technical support.
Ubuntu and Fedora are widely used by developers and are also popular in the educational realm. Scientific Linux is favored by the scientific research community for its compatibility with scientific and mathematical software packages.
Many commercial distributors, including Red Hat, Ubuntu, SUSE, and Oracle, provide long term fee-based support for their distributions, as well as hardware and software certification.
All major distributors provide update services for keeping your system primed with the latest security and bug fixes, and performance enhancements, as well as provide online support resources.
The Linux Foundation partners with the world’s leading developers and companies to solve the hardest technology problems and accelerate open technology development and commercial adoption.
The Linux Foundation makes it its mission to provide experience and expertise to any initiative working to solve complex problems through open-source collaboration, providing the tools to scale open-source projects: security best practices, governance, operations, and ecosystem development, training and certification, licensing, and promotion.