Free and open-source software (also known simply as Free software or Open source software) is software created by loose networks of people (both companies and individuals) who collaborated for mutual benefit. The software they produce is also made available for anyone else to freely download, use and modify because the developers also publish the human readable source code used to create it.

Making source code available means anyone with the programming ability can customize the software for their own ends or contribute to the development project directly. Others can help by reporting bugs and helping with documentation or translation efforts. So this encouragement of interaction between users and developers, and some users becoming developers, creates a positive feedback loop in the software’s evolution

Operating system is a set of programs containing instructions that coordinates all the activities along computer hardware resources. Most operating system perform similar function that includes starting a computer, provide a user interface, managing program, managing memory and configuring devices. Some operating system also allows user to control a network and administer security.

Examples of Free and Open Source Software for Operating Systems: Linux is a Unix-like and POSIX- compliant computer operating system assembled under the model of free and open source software development and distribution. The defining component of Linux is the Linux kernel, an operating system kernel first released on 5 October 1991 by Linus Torvalds.

Linux was originally developed as a free operating system for Intel x86-based personal computers. It has since been ported to more computer hardware platforms than any other operating system. It is a leading operating system on servers and other big iron systems such as mainframe computers and supercomputers. As of June 2013, more than 95% of the world’s 500 fastest supercomputers run some variant of Linux, including all the 44 fastest.

Linux also runs on embedded systems, which are devices whose operating system is typically built into the firmware and is highly tailored to the system; this includes mobile phones, tablet computers, network routers, facility automation controls, televisions and video game consoles. Android, which is a widely used operating system for mobile devices, is built on top of the Linux kernel.

The development of Linux is one of the most prominent examples of free and open source software collaboration. The underlying source code may be used, modified, and distributed-commercially or non- commercially-by anyone under licenses such as the GNU General Public License.

Ubuntu is a Debian-based Linux operating system, with Unity as its default desktop environment (GNOME was the previous desktop environment). It is based on free software and named after the Southern African philosophy of ubuntu (literally, “human-ness”), which often is translated as “humanity towards others” or “the belief in a universal bond of sharing that connects all humanity”.

Development of Ubuntu is led by Canonical Ltd., a company based on the Isle of Man and owned by South African entrepreneur Mark Shuttle worth. Canonical generates revenue through the sale of technical support and other services related to Ubuntu. The Ubuntu project is publicly committed to the principles of open source development; people are encouraged to use free software, study how it works, improve upon it, and distribute it.

Haiku is a free and open-source operating system compatible with the now discontinued BeOS. Its development began in 2001, and the operating system became self-hosting in The first alpha release was made in September 2009, and the most recent was November Haiku is supported by Haiku, inc., a non-profit organization based in Rochester, New York, founded in 2003 by former project leader Michael Phipps.

FreeBSD is a free Unix-like operating system descended from AT&TUnix via BSD. Although for legal reasons FreeBSD cannot be called “Unix,” it is a direct descendant from BSD, which was historically also called “BSD Unix” or “Berkeley Unix”. Due to its permissive licensing terms, much of FreeBSD’s code base has become an integral part of other operating systems such as Juniper JUNOS and Apple’s OS X. With the exception of the proprietary OS X, FreeBSD is the most widely used BSD-derived operating system in terms of number of installed computers, and is the most widely used freely licensed, open- source BSD distribution, accounting for more than three-quarters of all installed systems running free, open-source BSD derivatives.

NetBSD is an open-source Unix-like operating system descended from Berkeley Software Distribution (BSD), a Unix derivative developed at the University of California, Berkeley. It was the second open- source BSD descendant to be formally released, after 386BSD, and it continues to be actively developed. The NetBSD project is primarily focused on high-quality design, stability and performance of the system.

OpenIndiania is a free and open-source, Unix operating system derived from OpenSolaris. Developers forked OpenSolaris after Oracle Corporation discontinued it, in order to continue development and distribution of the source code. The OpenIndiania project is strewarded by the illumos Foundation, which also stewards the illumos operating system. OpenIndiania’s developers strive to make it “the defacto OpenSolaris distribution installed on production servers where security and bug fixes are required free of charge”.

Open SUSE is a general purpose operating system built on top of the Linux kernel, developed by the community-supported Open SUSE Project and sponsored by SUSE and a number of other companies. After Novell acquired SUSE Linux in January 2004, Novell decided to release the SUSE Linux Professional product as 100% open source project.

FreeDos (formerly Free-DOS and PD- DOS) is an operating system for IBM PC compatible computers. FreeDOS is made up of many different, separate programs that act as “packages” to the overall FreeDOS Project. FreeDOS supports vintage hardware IBM PCs as well as modern ones, in addition to embedded computers. Unlike MS-DOS, it is composed of free and open-source software, licensed under the terms of the GNU General Public License (GPL). Its “BASE” distribution does not require license fees or royalties and creation of custom distributions is permitted.