Introduction to Linux and Open Source
In this lesson, we will explore the world of Linux and open-source development. You will learn what distributions and derivatives are, how they are created and work, and the differences between free and open-source software.
We will explain how the GPL license works, the foundation of the Linux ecosystem, and review the pros and cons of free and paid solutions. This lesson will help you understand why Linux is a key tool for a system administrator and why Ubuntu is an ideal starting point for practice.
Linux and Its Evolution
Linux is an operating system created in 1991 by Linus Torvalds. Initially, he used Minix but was dissatisfied with its limitations and started developing his own system. After a pause, he returned to the project following an accidental corruption of a hard drive partition with Minix installed.
Linus Torvalds, creator of the Linux kernel. Source.Wikipedia
Linus wrote the kernel, inspired by Unix, and made it free and open for modification. The turning point was the adoption of the GNU GPL (General Public License), which allows anyone to use, modify, and distribute software. More on this later.
Interestingly, Linus initially wanted to call it Freax, but the server admin renamed it to Linux.
- Most servers worldwide run on Linux
- Almost all supercomputers use Linux
- Linux is the foundation of Android, the most widespread mobile OS
Linux’s popularity is due not only to its being free but also to its reliability, security, and active developer community support.
What is a Distribution?
A distribution is a complex software package that brings together the operating system and all necessary components for work. In Linux, a distribution is a bundle of essential components, each crucial for system operation and for connecting users, programs, and hardware.
- Kernel — the core, interacts with hardware
- System utilities — tools for managing files, processes, networks
- Package manager — for installing, updating, and removing software
- Repositories — online software stores
- Interfaces — command-line (CLI) and graphical (GUI)
Examples of popular distributions: Ubuntu, Debian, RHEL, Arch Linux
What is a Derivative?
A derivative is a version based on a main distribution, with its own modifications or improvements, but sharing the same kernel and repositories.
GPL License and the Philosophy of Free Software
Linux is distributed under the GNU GPL, which provides four freedoms: to use, study, modify, and distribute software.
Free Software and Open Source
The FSF and OSI promote similar ideas, but their emphasis differs: FSF focuses on user freedom, OSI on open development.
Advantages
- Cost savings (most programs are free)
- Security (source code is open for review)
- Independence
- Fast development
Challenges and Limitations
- High qualification requirements
- No commercial support
- Fragmentation risk
- Difficult to assess business value
Paid Solutions
RHEL and SLES are examples of commercial distributions with extended support and features.
Conclusion
All further course lessons will use Ubuntu (or your chosen distribution) as a platform. In the next lesson, we’ll guide you to download, install, and practice with a Linux system on a virtual machine!
