Linux

September 2nd, 2005

Best Free Operating System

Linux

Linux is one of the most prominent examples of free software and of open-source development: unlike other major ‘closed-source’ operating systems

(such as Windows or Mac OS) and programs, all of its underlying source code is available to the public and anyone can freely use, modify, and redistribute it.
In the narrowest sense, the term Linux refers to the Linux kernel, but it is commonly used to describe entire Unix-like operating systems (also known as GNU/Linux) that are based on the Linux kernel combined with libraries and tools from the GNU project. A linux distribution provides ease of installation and upgrades, and bundled software with the core system.

Initially, Linux was primarily developed and used by individual enthusiasts. Since then, Linux has gained the support of major corporations such as IBM, Hewlett-Packard and Novell for use in servers and is beginning to make inroads into the desktop market. Proponents and analysts attribute this success to its vendor independence, low cost, security, and reliability.

Linux was originally developed for Intel 386 microprocessors and now supports all popular computer architectures (and several obscure ones). It is deployed in applications ranging from personal computers to supercomputers and embedded systems such as mobile phones and personal video recorders.

History
The Linux kernel was initially written as a hobby by Finnish university student Linus Torvalds while attending the University of Helsinki. Torvalds originally used Minix on his computer, a simplified kernel written by Andrew Tanenbaum for teaching operating system design. However, Tanenbaum did not support extensions to his operating system, leading Torvalds to write a replacement for Minix. Linux started out as a terminal emulator written in IA-32 assembler and C which was compiled into binary form and booted from a floppy disk so that it would run outside of any operating system. The terminal emulator was running two threads: one for sending and one for receiving characters from the serial port. When Linus needed to write and read files to disk, this task-switching terminal emulator was extended with an entire filesystem handler, and after that gradually evolved into an entire operating system targeted at POSIX-compliance. Linus implemented enough POSIX system calls to make Linux run the Bash shell and after this bootstrapping procedure the development rapidly sped up. Although a running Minix system was originally necessary in order to configure, compile, install and run Linux, the Linux system quickly surpassed Minix in functionality and was soon able to boot on its own and compile its own source code.

Linus Torvalds, creator of the Linux kernelThe first version of the Linux kernel was released to the Internet in September 1991, with the second version following shortly thereafter in October [1]. Since then, thousands of developers around the world have participated in the project. Eric S. Raymond’s essay The Cathedral and the Bazaar discusses the development model of the Linux kernel and similar software.

The history of the Linux kernel is closely tied to that of GNU, a prominent free-software project led by Richard Stallman. The GNU project was announced in 1983 for the purpose of developing a complete Unix-like operating system, including software development tools and user application programs, composed entirely of free software. By the release of the first version of the Linux kernel, the GNU project had produced all the necessary components of this system except the kernel. Torvalds and other early Linux-kernel developers adapted their kernel to work with the GNU components and user space programs to create a fully functional operating system. The Linux kernel and operating system are licensed under the GNU General Public License (GPL) which requires that all source code modifications and derived works also be licensed under the GPL, which is generally referred to as a “share and share-alike” license. In 1997 Linus Torvalds stated, “Making Linux GPL’d was definitely the best thing I ever did.”

Tux the penguin is the logo and mascot of Linux (though there are other less common representations; see OS-tan). The name “Linux” was coined, not by Torvalds, but by Ari Lemmke, administrator at ftp.funet.fi, who named the FTP directory from which it was first available [3]. The Linux trademark (SN: 1916230) is owned by Linus Torvalds, registered for “Computer operating system software to facilitate computer use and operation.” The licensing of the trademark is now handled by the Linux Mark Institute.

Entry Filed under: Linux