Open source
Open source is a form of software. It is different from other software in that the source code is openly available for users to examine and modify, and to run or create computer programs. The source code is a set of instructions for the computer, written in a programming language.One of the best-known examples of open source software is Linux, which is widely used as an alternative to commercial operating system (OS) software. Open source software includes a license to use, modify, and redistribute the code. Commercially sold software products can be developed from open source software.
Anyone can see how the source code works and can change it if they want to make it work differently. The opposite of open source is closed source. Closed source software is not available to everyone. Open Source is almost the same thing as Free software.
A central features of open source software is that users can review the software, add features to it or hire programmers to add features, or fix errors known as bugs, rather than wait for the original software publisher or creator to release a “patch” or bring out a new version. With open source software, programmers—many of them nonprofessionals—contribute to the computing community by making their improvements and bug fixes available to other users.
Open Source and Free software have been around for decades. They became more popular with the Linux and BSD software communities. To protect the code, a special user license is used. The most common kinds of licence are the GPL, BSD and LGPL. Wikipedia uses open source too. The Open Source Movement is led by the Open Source Initiative.
The mere fact of making source code available does not make a program “open source,” according to the definition of open source provided by the Open Source Initiative, a nonprofit corporation. The organization’s formal definition specifies that, among other things, anyone has the right to modify and redistribute program code and derived works. The OSI definition of “open source” is roughly the same as the definition of “free software” advanced by the Free Software Foundation (FSF), founded by United States computer programmer Richard Stallman and embodied in the FSF’s General Public License (GPL). Stallman started the free software movement in 1983 when he announced plans to write a complete UNIX-compatible software system called GNU (which stands for GNU’s Not UNIX) and to give it away for free. Ultimately, this led to the creation of the GNU/Linux and GNU/Hurd operating systems.
The Open Source Initiative group distanced itself from the Free Software Foundation in 1998 when it adopted the open source label, arguing that “open source” carried less ideological baggage than “free software.” The group believed the phrase “open source” would have greater appeal to businesses, even though the software and the open approach were roughly the same as that put forward by the Free Software Foundation. Since 1998, the two movements have generally shifted in philosophy. The Open Source Initiative tends to view itself as a software development-related initiative; the Free Software Foundation views itself as a social movement.
The GNU/Linux operating system, usually called Linux, is the most successful and well-known example of open source software. Linux is a UNIX-like operating system that many use as an alternative to commercial UNIX or Windows operating systems. Finnish-born software engineer Linus Torvalds used GNU C—an open source version of the C programming language—to write the Linux operating system kernel and released it under the Free Software Foundation’s GPL, although it was not written as an FSF project.
