CentOS Stream 9 is one of several variants (also referred to as distributions) of the Linux operating system. It is based on the source code of the Red Hat Enterprise Linux distribution (RHEL), developed by a U.S. company named Red Hat, Inc. Based in Raleigh, North Carolina, the company was founded in the mid-1990s through the merger of two companies owned at the time by Marc Ewing and Bob Young. The origins of Linux, however, go back even further. This chapter will outline the history of the Linux operating system and Red Hat, Inc. before explaining how CentOS fits into this picture.

What exactly is Linux?

Linux is an operating system in much the same way that Windows is an operating system (and there any similarities between Linux and Windows end). The term operating system is used to describe the software that acts as a layer between the hardware in a computer and the applications that we all run on a daily basis. When programmers write applications, they interface with the operating system to perform such tasks as writing files to the hard disk drive and displaying information on the screen. Without an operating system, every programmer would have to write code to directly access the system’s hardware. In addition, the programmer would have to be able to support every single piece of hardware ever created to be sure the application would work on every possible hardware configuration. Because the operating system handles all of this hardware complexity, application development becomes much easier. Linux is just one of a number of different operating systems available today.

UNIX Origins

To understand the history of Linux, we first have to go back to AT&T Bell Laboratories in the late 1960s. During this time, AT&T had discontinued involvement in developing a new operating system named Multics. However, two AT&T engineers, Ken Thompson, and Dennis Ritchie, decided to take what they had learned from the Multics project and create a new operating system named UNIX which quickly gained popularity and wide adoption with corporations and academic institutions.

A variety of proprietary UNIX implementations eventually came to market, including those created by IBM (AIX), Hewlett-Packard (HP-UX), and Sun Microsystems (SunOS and Solaris). In addition, a UNIX-like operating system named MINIX was created by Andrew S. Tanenbaum and designed for educational use with source code access provided to universities.

Who Created Linux?

The origins of Linux can be traced back to the work and philosophies of two people. At the heart of the Linux operating system is something called the kernel. This is the core set of features necessary for the operating system to function. The kernel manages the system’s resources and handles

communication between the hardware and the applications. The Linux kernel was developed by Linus Torvalds, who, taking a dislike to MS-DOS and impatient for the availability of MINIX for the new Intel 80386 microprocessor, decided to write his own UNIX-like kernel. When he had finished the first version of the kernel, he released it under an open-source license that enabled anyone to download the source code and freely use and modify it without having to pay Linus any money.

Around the same time, Richard Stallman at the Free Software Foundation, a strong advocate of free and open-source software, was working on an open-source operating system of his own. Rather than focusing initially on the kernel, however, Stallman began by developing open-source versions of all the UNIX tools, utilities, and compilers necessary to use and maintain an operating system. By the time he had finished developing this infrastructure, the obvious solution was to combine his work with the kernel Linus had written to create a complete operating system. This combination became known as GNU/Linux. Purists insist that Linux always be referred to as GNU/Linux (in fact, at one time, Richard Stallman refused to give press interviews to any publication which failed to refer to Linux as GNU/Linux). This is not unreasonable, given that the GNU tools developed by the Free Software Foundation make up a significant and vital part of GNU/Linux. Unfortunately, most people and publications refer to Linux as Linux, which will probably always continue to be the case.

The Early Days of Red Hat

In 1993 Bob Young created a company named ACC Corporation which, according to Young, he ran from his “wife’s sewing closet”. The name ACC was intended to represent a catalog business but was also an abbreviation of a small business his wife ran called “Antiques and Collectibles of Connecticut”. Among the items sold through the ACC catalog business were Linux CDs and related open-source software.

Around the same time, Marc Ewing had created his own Linux distribution company, which he named Red Hat Linux (after his propensity to wear a red baseball cap while at Carnegie Mellon University).

In 1995, ACC acquired Red Hat, adopted the name Red Hat, Inc., and experienced rapid and significant growth. Bob Young stepped down as CEO shortly after the company went public in August of 1999 and has since pursued a number of business and philanthropic efforts, including a print-on-demand book publishing company named Lulu and ownership of two Canadian professional sports teams. In 2018, IBM acquired Red Hat, Inc. in a deal valued at $34 billion.

Red Hat Support

Early releases of Red Hat Linux were shipped to customers on floppy disks and CDs (this, of course, predated the widespread availability of broadband internet connections). When users encountered problems with the software, they could only contact Red Hat by email. In fact, Bob Young often jokes that this was effective in limiting support requests since, by the time a customer realized they needed help, their computer was usually inoperative and therefore unavailable to be used to send an email message seeking assistance from Red Hat’s support team. In later years, 6

Red Hat provided better levels of support tied to paid subscriptions and now provides a variety of support levels ranging from “self-help” (no support) up to premium support.

Open Source

Red Hat Enterprise Linux 9 is the current commercial offering from Red Hat and is primarily targeted at corporate, mission-critical installations. It is also the cornerstone of an expanding ecosystem of products and services Red Hat offers. RHEL is an open-source product in that you can download the source code free of charge and build the software yourself if you wish to do so (a task not to be undertaken lightly). If, however, you wish to download a pre-built, ready-to-install binary version of the software (either with or without support), you have to pay for it.

The Fedora Project

Red Hat also sponsors the Fedora Project, the goal of which is to provide access to a free Linux operating system (in both source and binary distributions) in the form of Fedora Linux. Fedora Linux also serves as a proving ground for many of the new features that are eventually adopted into the Red Hat Enterprise Linux operating system family and the CentOS derivative.

CentOS Stream – The Free Alternative

For users unable to afford a Red Hat Enterprise Linux subscription, another option is the CentOS Stream operating system. The CentOS project, initially a community-driven effort but now owned by Red Hat, takes the Red Hat Enterprise Linux source code, removes the Red Hat branding and subscription requirements, compiles it, and provides the distribution for download. Like Fedora, CentOS Stream field tests new operating system features before they are included in a future RHEL release. As such, it may lack stability but provides access to cutting-edge features.

Summary

The origins of the Linux operating system can be traced back to the work of Linus Torvalds and Richard Stallman in the form of the Linux kernel combined with the tools and compilers built by the GNU project.

Over the years, the open-source nature of Linux has resulted in the release of a wide range of different Linux distributions. One such distribution is Red Hat Enterprise Linux, created by Red Hat, Inc., a company founded by Bob Young and Mark Ewing. Red Hat specializes in providing enterprise-level Linux software solutions combined with extensive technical support services. CentOS Stream 9 is developed in close collaboration with Red Hat, Inc. and serves as a proving ground for the new features that will eventually be included in future Red Hat Enterprise Linux releases.