What is Open Source?

“The term ‘open source’ describes practices in production and development that promote access to the end product's source materials”.Lots of phrases have been used to describe the concept of “open source” before the community adopted this term, and the rise of the Internet, and the need of adjusting and reusing the source code helped “open source” to get accepted.

“Open source” should not be confused with another term, “free software”, and they are not synonymous. Normally free software refers to the price of the software. For example, Google’s Gmail is an example of a free, closed source application. However, open source is a matter of users’ freedom to run, copy, distribute, study, change, and improve the software.

More precisely, it refers to four types of freedom, for the users of the software:

• The freedom to run the program, for any purpose;
• The freedom to study how the program works, and adapt it to your needs (Access to the source code is a precondition for this);
• The freedom to redistribute copies so you can help your neighbor;
• The freedom to improve the program, and release your improvements to the public, so that the whole community benefits (Access to the source code is a precondition for this).

In contrast, proprietary software is licensed under exclusive legal right of the copyright holder. The licensee is given the right to use the software under certain conditions, but restricted from other uses, such as modification, further distribution, or reverse engineering. In other words, proprietary software is closed-source, therefore the source code of application is not released to the users. For example, Microsoft, which owns and develops Windows and Microsoft Office, has been proponents of this business model.

Many free open source systems such as WordPress are released under GNU’s General Public License (GPL), which is intended to guarantee the freedom to share and change all versions of a program, and to make sure it remains free software for all its users. GPL also allows any user to modify or redistribute the source code and all derivative works.