Open Source
The term open source refers to something that is publicly available so that people can modify and share it.
The term originated in the field of software development, referring to a specific method for creating computer programs. Today, however, "open source" represents a broader range of values - what you could call the "open source way." An open source project, product, or initiative embraces and promotes the principles of open communication, collaborative participation, rapid prototyping, transparency, meritocracy, and community-oriented development.
What is open source software
Open source software is software with source code that anyone can inspect, modify, and enhance.
"Source code" is the part of software that most computer users never see; it is the code that computer programmers can manipulate to change the way the software ("program" or "application") works. Programmers who have access to a computer program's source code can improve that program by adding features or fixing parts that don't work properly.
How open source software differs from other types of software
Some software has source code that can only be modified by the person, team, or organization that created it and has exclusive control over it. People call this software "proprietary" or "closed source" software.
Only the original author of proprietary software can legally copy, inspect, and modify the software. In order to use proprietary software, computer users must agree (usually by signing a license displayed when they first run the software) that they will not use the software for anything not expressly permitted by the software's author. Microsoft Office and Adobe Photoshop are examples of proprietary software.
Open source software, on the other hand, is software whose authors make their source code available to others who want to view, copy, study, modify, or share the code. As with proprietary software, users must accept the terms of a license when using open source software—but the legal terms of an open source license are very different from those of a proprietary license.
Open source licenses affect how people use, study, modify, and distribute software. Generally, open source licenses give computer users permission to use the open source software for any purpose. Some open source licenses (some call them "copyleft" licenses) require that anyone who distributes modified versions of the open source program also distribute the program's source code. In addition, some open source licenses require that anyone who modifies and shares the program with others also share the program's source code, without charging a licensing fee.
Open source software licenses are designed to promote collaboration and sharing because they allow others to modify the source code and incorporate those changes into their own projects. They encourage computer programmers to access, review, and modify open source software at any time, as long as they allow others to do the same when they share their work.