Open-source software is also called as OSS, which is a computer software program designed and deployed with its source code made available and licensed with a free license in which the copyright holder provides the rights to an anonymous entity for any purpose. People using OSS can distribute the software to anyone and for any purpose because Open-source software is very often developed in a public, collaborative manner. Open-source software is the most prominent example of open-source development and often compared to (technically defined) user-generated content or (legally defined) open-content movements.
The top Five reasons why individuals or organizations choose open source software are:
1) Lower cost,
3) No vendor 'lock in', and
4) Better quality
The Open source code modification, redistribution of open-source software reserved under copyright holder according to copyright law. GNU General Public License (GPL), is a good example of it which allows free distribution under the same license for its free usage. Software licenses grant rights to users, which would otherwise be reserved by copyright law to the copyright holder. Among thousands of Open source software projects these 10 Open Source Softwares listed below are the most important and valuable. These are rare software product that has no alternatives and must require.
1) Linux kernel
The Linux kernel is a prominent example of free and open source software. It is a Unix-like operating system released under the GNU General Public License version (GPLv2). Linux wasn't the first open source software project, but it was the powerful community developed by contributors worldwide. The Linux kernel is used by a variety of operating systems based on it, which are usually in the form of Linux distributions. The popularity of Linux Kernel rapidly accumulated developers and users who adopted code from other free software projects for use with the new operating system.
2) GNU Utilities and Compilers
The GNU Project is the flagship of the free software movement and Compiler Collection, which is also named as GNU Compiler Collection (GCC) which is developed by the GNU Project supporting various programming languages. The Free Software Foundation (FSF) distributes GCC under the GNU General Public License (GNU GPL), which is the source of an amazing variety of tools and utilities that, when combined with the Linux kernel, provide a complete operating system.
With the Linux kernel, the GNU utilities and the GNU Compiler Collection make up the holy trinity of the Linux world. As well as being the official compiler of the unfinished GNU operating system, GCC has been adopted as the standard compiler by most other modern Unix-like computer operating systems, including Linux and the BSD family. Versions are also available for Microsoft Windows and other operating systems. GCC is also available for most embedded platforms, including Symbian (called gcce), AMCC, and Freescale Power Architecture-based chips. It is named the GNU C Compiler, because it only handled the C programming language and the compiler was extended to compile C++ in December of that year 1987.
Ubuntu is a Debian-based Linux operating system developed to increase usability and ease of use. Ubuntu is a free software and named after the Southern African philosophy of Ubuntu (literally, "humanness"), which often is translated as "humanity towards others" or "the belief in a universal bond of sharing that connects all humanity". Ubuntu is the first choice of novice users and PC sellers because its free and no need to pay fees. 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.
According to some metrics, Ubuntu is the most popular desktop Linux distribution. Ubuntu comes installed with a wide range of software that includes LibreOffice, Firefox, Empathy, Transmission, and several lightweight games.
4) BSD Operating Systems
Linux isn't the only popular free open source operating system, there are a number of Unix-like operating systems under active development, named behind BSD (Berkeley Software Distribution). Free BSD, Net BSD and OpenBSD are very famous examples of the BSDs.
FreeBSD is famous for superior reliability and performance. It’s a free Unix-like operating system developed by AT&T UNIX and has more than 200 active developers and thousands of contributors.
NetBSD is a freely redistributable, open source version of the Unix-derivative BSD, computer operating system notable for supporting a wide range of hardware platforms, including embedded systems and mobile devices. NetBSD is famous for its portability and quality of design and implementation, it is often used in embedded systems and as a starting point for the porting of other operating systems to new computer architectures.
OpenBSD is touted as perhaps the most secure Unix-like operating system, with a security audit that never stops. It includes a number of security features absent or optional in other operating systems and has a tradition of developing auditing the source code for software bugs and security problems.
Samba is Free Software licensed under the GNU General Public License, the Samba project is a member of the Software Freedom Conservancy. Samba is a free software re-implementation of the SMB/CIFS networking protocol, originally developed by Andrew Tridgell. Samba bridges the gaps between Linux/Unix and Windows, allowing Unix and Linux servers to provide file and print services to Windows clients, and Linux and Unix clients work with Windows file servers. A Samba host can even serve as the primary domain controller for a Windows network. Samba provides file and print services for various Microsoft Windows clients and can integrate with a Windows Server domain, either as a Primary Domain Controller (PDC) or as a domain member. Samba is released under the terms of the GNU General Public License. The name Samba comes from the SMB (Server Message Block), the name of the standard protocol used by the Microsoft Windows network file system.
The world's most popular open source database with easy administration, excellent read performance, and transparent support for large text and binary objects make it the top choice for many Web sites. The MySQL development project has made its source code available under the terms of the GNU General Public License, as well as under a variety of proprietary agreements. It is a popular choice of database for use in web applications, and is a central component of the widely used LAMP open source web application acronym for "Linux, Apache, MySQL, Perl/PHP/Python." Free-software-open source projects that require a full-featured database management system often uses MySQL. Applications which use MySQL databases include: TYPO3, MODx, Joomla, WordPress, phpBB, MyBB, Drupal and other software.
BIND is the most popular open source DNS (Domain Name System) server software on the Internet. It works on Unix-like operating systems, it is the de facto standard that implements DNS protocols for the Internet. The Berkeley Internet Name Domain package was originally written at the University of California at Berkeley. The software consists, most prominently, of the DNS server component, called contracted for name daemon. In addition the suite contains various administration tools, and a DNS resolver interface library. The latest version of BIND is BIND 9, first released in 2000.
Sendmail is a general purpose internetwork email routing facility born before the Internet was standardized and supports different kinds of mail-transfer and delivery methods, including the Simple Mail Transfer Protocol (SMTP) used for email transport over the Internet. Sendmail served as the backbone of the Internet mail system throughout the 1980s and 1990s. It has lost ground to Postfix, Qmail, Exim, and Microsoft Exchange in recent years, but still ranks among the most popular MTAs (mail transfer agents). It is a well-known project of the free and open source software and Unix communities. It has spread both as free software and proprietary software.
9) OpenSSH and OpenSSL
OpenSSH is an abbreviation of OpenBSD Secure Shell developed as part of the security conscious OpenBSD project. It is a set of computer programs providing encrypted communication sessions over the Internet using the SSH protocol. It was created as an open source alternative to the proprietary Secure Shell software suite offered by SSH Communications Security.
OpenSSL is an open-source implementation software package uses strong cryptography. OpenSSH encrypts shell communications to remote computers, addressing the shortcomings in tools such as rlogin and telnet, which send usernames and passwords in clear text. OpenSSL is a software library that allows developers to incorporate SSL or TLS into their Internet applications. It was written in the C programming language, implements the basic cryptographic functions and provides various utility functions. The project is managed by a worldwide community of volunteers that use the Internet to communicate, plan, and develop the OpenSSL toolkit and its related documentation.
The Apache HTTP Server Project is an effort to develop and maintain an open-source HTTP server for modern operating systems including UNIX and Windows. The Web server that puts the A in LAMP is still fast, flexible, and secure, with broad operating system and Web programming language support and hundreds of modules available to extend the functionality. Apache is developed and maintained by an open community of developers under the auspices of the Apache Software Foundation. The goal of this project is to provide a secure, efficient and extensible server that provides HTTP services in sync with the current HTTP standards.
Apache httpd has been the most popular web server on the Internet and generally used on a Unix-like system, the software is available for a wide variety of operating systems, including Unix, FreeBSD, Linux, Solaris, Novell NetWare, OS X, Microsoft Windows, OS/2, TPF, OpenVMS and eComStation. Released under the Apache License, Apache is open-source software.