Open Source Operating Systems and Development
INTRODUCTION When you use a Linux desktop such as GNOME, KDE Plasma, Xfce, Cinnamon, or LXQt, there is a graphics system working behind the scenes that displays windows, handles mouse and keyboard input, and communicates with your graphics hardware. For decades, Linux desktops relied on the X Window System, commonly called X11 or Xorg. In … Read More “UNDERSTANDING XORG AND WAYLAND” »
If your goal is to learn Linux system programming, operating systems, networking, or kernel concepts, you do not need to master all of C first. You need a solid understanding of variables, loops, functions, arrays, pointers, and structs. This tutorial covers the essentials. Your First C Program Every C program starts execution in the main() … Read More “Learn Just Enough C for Linux Programming” »
Introduction One of the best ways to learn C programming is by working directly from the command line. While modern IDEs provide many conveniences, using the Terminal teaches you how programs are actually compiled, linked, and executed. On a MacBook M1 (Apple Silicon), C development is built into macOS through Apple’s developer tools. The default … Read More “Writing C Programs from the Command Line on a MacBook M Series” »
Introduction One of the reasons C remains important today is that operating systems such as FreeBSD and Linux are largely written in C. At first glance, C programming on FreeBSD and Linux appears almost identical. Both systems provide a POSIX-compatible environment, use the GCC or Clang compilers, and offer similar development tools. However, there are … Read More “C Programming on FreeBSD vs Linux” »
Introduction More than fifty years after its creation, UNIX remains one of the most influential technologies in computing history. Although relatively few people use a traditional UNIX system directly today, its ideas, architecture, and philosophy continue to shape nearly every aspect of modern computing. From Linux servers and cloud infrastructure to smartphones and enterprise systems, … Read More “UNIX’s Influence Today: The Operating System That Shaped Modern Computing” »
Introduction When people discuss Linux, they often focus on the Linux kernel and its creator, Linus Torvalds. However, the success of Linux would have been far less likely without the GNU Project, one of the most influential software initiatives in computing history. The GNU Project provided many of the tools, libraries, compilers, and utilities that … Read More “The Role of GNU: Building the Foundation of Free Software” »
Introduction When Finnish computer science student Linus Torvalds announced a small hobby operating system project in 1991, few people imagined it would become one of the most important technologies in history. Today, Linux powers the majority of the world’s servers, most cloud infrastructure, all of the top supercomputers, billions of Android devices, embedded systems, smart … Read More “Why Linux Succeeded: The Story of an Operating System That Changed Computing” »
Introduction Every Linux system connected to a network needs a firewall. Firewalls control which network traffic is allowed to enter or leave a machine, helping protect servers, desktops, laptops, and embedded systems from unauthorized access. Modern Linux systems use the Linux kernel’s Netfilter framework for packet filtering and firewall functionality. Over the years, several tools have been … Read More “An In-Depth Look at nftables, firewalld, and UFW” »
Introduction For many years, iptables has been the primary firewall management tool on Linux systems. It allows administrators to control network traffic entering, leaving, and passing through a Linux machine. While newer systems increasingly use nftables, iptables remains widely used and understanding it provides valuable insight into Linux networking and security. This article explores how iptables works … Read More “An In-Depth Look at iptables” »
Introduction Every time a Linux system loads a web page, sends an email, streams a video, or connects to a remote server, network packets travel through the Linux kernel. While applications such as web browsers and SSH clients generate and consume data, it is the kernel that performs the actual work of moving packets between … Read More “How the Linux Kernel Processes Packets” »