What is Open Source Software?

You might not realize it but you use open source software almost every day

Developers at work
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Open source software (OSS) is software for which the source code is viewable and changeable by the public, or otherwise "open". When the source code is not viewable and changeable by the public, it's considered "closed" or "proprietary".

Source code is the behind-the-scenes programming part of software that users don't usually look at. Source code lays out the instructions for how the software works and how all of the different features of the software work.

How Users Benefit from OSS

OSS allows programmers to collaborate on improving the software by finding and fixing errors in the code (bug fixes), updating the software to work with new technology, and creating new features. The group collaboration approach of open source projects benefits users of the software because errors are fixed faster, new features are added and released more frequently, the software is more stable with more programmers to look for errors in the code, and security updates are implemented faster than many proprietary software programs.

Most OSS uses some version or variation of the GNU General Public License (GNU GPL or GPL). The simplest way to think of a GPL similar to a photo that is in the public domain. GPL and public domain both allow anyone to modify, update, and reuse something however they need to. The GPL gives programmers and users the permission to access and change the source code, whereas public domain gives users the permission to use and adapt the photo.

The GNU part of GNU GPL refers to the license created for the GNU operating system, a free/open operating system that was and continues to be a significant project in open source technology.

Another bonus for users is that OSS is generally free, however, there may be a cost for extras, such as technical support, for some software programs.

Where Did Open Source Come From?

While the concept of collaborative software coding has its roots in 1950-1960s academia, by the 1970s and 1980s, issues such as legal disputes caused this open collaboration approach for software coding to lose steam. Proprietary software took over the software market until Richard Stallman founded the Free Software Foundation (FSF) in 1985, bringing open or free software back to the forefront. The concept of "free software" refers to freedom, not cost. The social movement behind free software maintains that software users should have the freedom to see, change, update, fix, and add to source code to meet their needs, and to be allowed to distribute it or share it freely with others.

The FSF played a formative role in the free and open source software movement with their GNU Project. GNU is a free operating system (a set of programs and tools that instruct a device or computer how to operate), typically released with a set of tools, libraries, and applications that together may be referred to as a version or a distribution. GNU is paired with a program called a kernel, which manages the different resources of the computer or device, including communications back and forth between software applications and the hardware.

The most common kernel paired with GNU is the Linux kernel, originally created by Linus Torvalds. This operating system and kernel pairing is technically called the GNU/Linux operating system, though it is often referred to simply as Linux.

For a variety of reasons, including confusion in the marketplace over what the term "free software" truly meant, the alternate term "open source" became the preferred term for software created and maintained using the public collaboration approach. The term "open source" was officially adopted at a special summit of technology thought-leaders in February 1998, hosted by technology publisher Tim O'Reilly.

Later that month, the Open Source Initiative (OSI) was founded by Eric Raymond and Bruce Perens as a non-profit organization dedicated to promoting OSS.

The FSF continues as an advocacy and activist group dedicated to supporting users' freedoms and rights related to use of source code. However, much of the technology industry uses the term "open source" for projects and software programs that allow public access to source code.

Open Source Software is Part of Everyday Life

Open source projects are a part of our daily lives. You might be reading this article on your cell phone or tablet, and if so, you are likely using open source technology right now. The operating systems for both iPhone and Android were originally created using building blocks from open source software, projects, and programs.

If you are reading this article on your laptop or desktop, are you using Chrome or Firefox as the web browser? Mozilla Firefox is an open source web browser. Google Chrome is a modified version of the open source browser project called Chromium--though Chromium was started by Google developers who continue to play an active role in the updating and additional development, Google has added programming and features (some of which are not open source) to this base software to develop the Google Chrome browser.

In fact, the internet as we know it would not exist without OSS. The technology pioneers that helped build the world wide web used open source technology, such as the Linux operating system and Apache web servers to create our modern-day internet. Apache web servers are OSS programs that process a request for a certain webpage (for example, if you click on a link for a website you'd like to visit) by finding and taking you to that webpage. Apache web servers are open source and are maintained by developer volunteers and members of the non-profit organization called the Apache Software Foundation.

Open source is recreating and reshaping our technology and our daily lives in ways we often don't realize. The global community of programmers who contribute to open source projects continue to grow the definition of OSS and add to the value it brings to our society.