History

Linux Ideas and History .....

Linux is a Unix-like computer Operating System (or OS). Linux started out as a personal computer system used by individuals, and has since gained the support of several large  corporations, such as Sun Microsystems, HP and IBM. It is now used mostly as a server operating system, with some large organizations using an enterprise version for desktops. Linux is a prime example of open-source development, which means that the source code is available freely for anyone to use. Linus Torvalds, who was then a student at the University of Helsinki in Finland, developed Linux in 1991. He released it for free on the Internet. Due to the far reach of the Free Software Foundation (FSF) and the GNU Project, Linux popularity increased rapidly, with utilities developed and released for free online. A commercial version of Unix was released by RedHat in the early 1990’s (combining the OS with technical support and documentation) and the popularity of Linux continued to skyrocket. 
 The Unix operating system was conceived and implemented in 1969 at AT&T's Bell Laboratories in the United States by Ken Thompson, Dennis Ritchie, Douglas McIlroy, and Joe Ossanna. Unix derived its name as a joke and reference to an experimental operating system that was slow and ineffective called MULTICSMultiplexed Information and Computing Service ). It was first released in 1971. Unix was re-written in the programming language C by Dennis Ritchie.

The development of Linux is one of the most prominent examples of free and open source software collaboration; typically all the underlying source code can be used, freely modified, and redistributed, both commercially and non-commercially, by anyone under licenses such as the GNU General Public License. Typically Linux is packaged in a format known as a Linux distribution for desktop and server use. Linux distributions include the Linux kernel and all of the supporting software required to run a complete system, such as utilities and libraries, the X Window System, the GNOME and KDE desktop environments, and the Apache HTTP Server. Commonly used applications with desktop Linux systems include the Mozilla Firefox web-browser, the OpenOffice.org office application suite and the GIMP image editor

 

GNU  The GNU Project, started in 1984 by Richard Stallman, had the goal of creating a "complete Unix-compatible software system" composed entirely of free software. Work began in 1984. Later, in 1985, Stallman started the Free Software Foundation and wrote the GNU General Public License (GNU GPL) in 1989. By the early 1990s, many of the programs required in an operating system (such as libraries, compilers, text editors, a Unix shell, and a windowing system) were completed, although low-level elements such as device drivers, daemons, and the kernel were stalled and incomplete. Linus Torvalds has said that if the GNU kernel had been available at the time (1991), he would not have decided to write his own.

MINIX was an inexpensive minimal Unix-like operating system, designed for education in computer science, written by Andrew S. Tanenbaum. Starting with version 3, MINIX is free and redesigned also for "serious" use. In 1991 while attending the University of Helsinki, Torvalds, curious about the operating systems [and frustrated by the licensing of MINIX limiting it to educational use only (which prevented any commercial use) began to work on his own operating system which eventually became the Linux kernel.

Torvalds began the development of the Linux kernel on MINIX and applications written for MINIX were also used on Linux. Later Linux matured and it became possible for Linux to be developed under itself. Also GNU applications replaced all MINIX ones because, with code from the GNU system freely available, it was advantageous if this could be used with the fledgling operating system. Code licensed under the GNU GPL can be used in other projects, so long as they also are released under the same or a compatible license. In order to make the Linux available for commercial use, Torvalds initiated a switch from his original license (which prohibited commercial redistribution) to the GNU GPL. Developers worked to integrate GNU components with Linux to make a fully functional and free operating system.

Fortune 500 companies, governments, and consumers more and more use Linux as a cost-effective computing solution. It has been used and is still used by big companies like IBM, Amtrak, NASA, and others.

Every Linux distribution comes with more than 18,000 pages of documentation. Commercial Linux distributions such as Red Hat Linux, Caldera, SuSE, Fedora, Ubuntu, Sun and OpenLinux offer initial support for registered users, and small business and corporate accounts can get 24/7 supports through a number of commercial support companies. As an Open Source operating system, there's no six months to wait for a service release, and the online Linux community fixes many serious bugs within hours. Linux can be generally divided into three major components:

The kernel, the environment and the file structure. The kernel is the core program that runs programs and manages hardware devices, such as disks and printers. The environment provides an interface for the user. It receives commands from the user and sends those commands to the kernel for execution. The Files structure organizes the way files are stored on a storage devices, such a s a disk. Files are organized into directories. Each directory may contain any number of subdirectories, each holding files. Together, the kernel, the environment and the file structure from the basic operating system structure. With these three you can run programs, manage files and interact with the system.

An environment provides an interface between the kernel and the user. It can be described as an interpreter. Such an interface commands entered by the user and sends them into the kernel. Linux provides several kinds of environments: desktops, window managers and commands line shells. Each user on a Linux system has his or her own user interface. Users can tailor their environments to their own special needs, whether they be shells, window managers, or desktops. In this sense for the user, the OS functions more as operating environment, which the user can control.

In Linux, files are organized into directories, much as they are in windows. The entire Linux file system is one large interconnected set of directories, each containing files. Some directories are standard directories reserved for system use. You can create your own directories for your own files, as well as easily move files from one directories to another. You can even move entire directories and share directories and files with other users on your system. With Linux you can also set permissions on directories and files, allowing others to access them or restricting access to yourself alone. The directories of each user are in fact, ultimately connected to directories of the users. Directories are organized into a hierarchical tree structure, beginning with an initial root directories. All other directories are ultimately derived from this first root directory.

With the K Desktop Environment (KDE) and the GNU Network Object Model Environment (GNOME), Linux now has a completely integrated GUI interface. You can perform all your Linux operations entirely from either interface. KDE and GNOME are fully operational desktops supporting drag-and-drop operations, enabling you to drag icons to your  Desktop and to set up your own menus on an applications panel. Both rely on an underlying X window system, which means as long as they are both installed on your system, applications from one can run on the other desktop. The gnome and KDE sites are particularly helpful for documentations, news and software you can download for those desktop. Both desktops can run any X window system program, as well as any cursor-based program such as Emacs and vi, which were designed to work in a shell environment. At the same time, a great many applications are written just for those desktops and included with your distributions. The K desktops has a complete set of internet tools along with editors and graphics, multimedia and system applications. Gnome has slightly fewer applications, but a great many are currently in the works. Check their web sites at www.gnome.org and www.kde.org for new applications. As new versions are released, they include new software.