Linux, Linux

Later Linux matured and it became possible for Linux to be developed under itself.

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 kernel compatible with the components from the GNU Project, Torvalds initiated a switch from his original license (which prohibited commercial redistribution) to the GNU GPL.

Linux vendors and communities combine and distribute the kernel, GNU components, and non-GNU components, with additional package management software in the form of Linux distributions.

It derives much of its basic design from principles established in Unix during the 1970s and 1980s. Such a system uses a monolithic kernel, the Linux kernel, which handles process control, networking, and peripheral and file system access. Device drivers are integrated directly with the kernel.

The graphical user interface (or GUI) used by most Linux systems is based on the X Window System.

A Linux distribution specialized for servers may use the CLI as its only interface. A headless system run without even a monitor can be controlled by the command line via a remote-control protocol such as SSH or telnet.

A graphical terminal emulator program is often used to access the CLI from a Linux desktop.

Linux is not the only such operating system, although it is by far the most widely used. Some free and open source software licenses are based on the principle of copyleft, a kind of reciprocity: any work derived from a copyleft piece of software must also be copyleft itself. The most common free software license, the GNU GPL, is a form of copyleft, and is used for the Linux kernel and many of the components from the GNU project.

Linux systems adhere to POSIX, SUS, ISO and ANSI standards where possible, although to date only one Linux distribution has been POSIX.1 certified, Linux-FT.

The fact that the software licenses explicitly permit redistribution, however, provides a basis for larger scale projects that collect the software produced by stand-alone projects and make it available all at once in the form of a Linux distribution.

This allows the user to adapt the operating system to his/her specific needs. Distributions are maintained by individuals, loose-knit teams, volunteer organizations, and commercial entities. A distribution can be installed using a CD that contains distribution-specific software for initial system installation and configuration. A package manager such as Synaptic allows later package upgrades and installations. A distribution is responsible for the default configuration of the installed Linux kernel, general system security, and more generally integration of the different software packages into a coherent whole.

Linux distributions host mailing lists; commonly there will be a specific topic such as usage or development for a given list.

Print magazines on Linux often include cover disks including software or even complete Linux distributions.

These include Dell, IBM, HP, Oracle, Sun Microsystems, Novell, Nokia. A number of corporations, notably Red Hat, have built their entire business around Linux distributions.

Amongst others, GCC provides compilers for Ada, C, C++, Java, and Fortran. The Linux kernel itself is written to be compiled with GCC. Proprietary compilers for Linux include the Intel C++ Compiler, Sun Studio, and IBM XL C/C++ Compiler.

A number of Java Virtual Machines and development kits run on Linux, including the original Sun Microsystems JVM (HotSpot), and IBM's J2SE RE, as well as many open-source projects like Kaffe.

The Linux kernel runs on a highly diverse range of computer architectures: in the hand-held ARM-based iPAQ and the mainframe IBM System z9, in devices ranging from mobile phones to supercomputers.

Commonly, either a free software application will exist which does the functions of an application found on another operating systems, or that application will, in fact, work on Linux (such as Skype). Furthermore, the Wine project provides a Windows compatibility layer to run unmodified Windows applications on Linux. CrossOver is a proprietary solution based on the open source Wine project that supports running Windows versions of Microsoft Office, Intuit applications such as Quicken and QuickBooks, Adobe Photoshop versions through CS2, and many popular games such as World of Warcraft and Team Fortress 2 . In other cases, although there is no Linux port of some software in areas such as desktop publishing and professional audio, there is equivalent software available on Linux.

In the field of animation and visual effects, most high end software, such as AutoDesk Maya, Softimage XSI and Apple Shake, is available for Linux, Windows and/or Mac OS X.

In this case the Lanka Linux User Group played a major part in developing the localized system by combining the knowledge of university professors, linguists, and local developers.

Linux has become a major competitor to the proprietary Symbian OS found in the majority of smartphones16.7% of smartphones sold worldwide during 2006 were using Linux and it is an alternative to the proprietary Windows CE and Palm OS operating systems on mobile devices. Cell phones or PDAs running on Linux and built on open source platform became a trend from 2007, like Nokia N810, Openmoko's Neo1973, Motorola RAZR2 v8, Motorola ROKR E8, Motorola MING series, Motorola ZINE and the on-going Google Android. The popular TiVo digital video recorder uses a customized version of Linux.

Since then major studios like Dreamworks Animation, Pixar and Industrial Light & Magic have moved to Linux.

The GPL requires that anyone who distributes the Linux kernel must make the source code (and any modifications) available to the recipient under the same terms. In 1997, Linus Torvalds stated, Making Linux GPL'd was definitely the best thing I ever did. Other key components of a Linux system may use other licenses; many libraries use the GNU Lesser General Public License (LGPL), a more permissive variant of the GPL, and the X Window System uses the MIT License.

Slightly over half of all lines of code were licensed under the GPL. The Linux kernel itself was 2.4 million lines of code, or 8% of the total.

The naming issue remains controversial. Linus Torvalds is against the GNU/Linux naming, stating that Linux is not a GNU project.

Source: Wikipedia > Linux