Free and Open-Source Software

What Does Free and Open-Source Software Mean?

Free and open-source software (FOSS) allows users and programmers to edit, modify or reuse the software’s source code. This gives developers the opportunity to improve program functionality by modifying it.


The term “free” indicates that the software does not have constraints on copyrights. The term “open source” indicates the software is in its project form, enabling easy software development from expert developers collaborating worldwide without any need for reverse engineering.

Free and open-source software may also be referred to as free/libre open-source software (FLOSS) or free/open-source software (F/OSS).

Techopedia Explains Free and Open-Source Software

Before 1960, most software was openly accessible and free because software tools required a relatively simple development effort. As the complexity of software applications grew, this led to greater software package development efforts, making software licensing a market trend. Eventually, developers found techniques to avoid multicomputer software use, such as use of product keys and Internet activation. With the widespread use of the Internet, these techniques became essential for developers to regain profit from their efforts.

FOSS surfaced as a result of a need for free, collaborative effort in complicated and expensive projects. Today, many FOSS projects are available for active developers.


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.