Open Source Software

- Overview

Open source software (OSS) is software that is distributed with its source code, making it available for use, modification, and distribution with its original rights. 

Source code is the part of software that most computer users don’t ever see; it’s the code computer programmers manipulate to control how a program or application behaves. Programmers who have access to source code can change a program by adding to it, changing it, or fixing parts of it that aren’t working properly. 

OSS typically includes a license that allows programmers to modify the software to best fit their needs and control how the software can be distributed.

- How Does OSS Work?

Open source code is usually stored in a public repository and shared publicly. Anyone can access the repository to use the code independently or contribute improvements to the design and functionality of the overall project. 

OSS usually comes with a distribution license. This license includes terms that define how developers can use, study, modify, and most importantly, distribute the software.iii According to the Synopsys Black Duck® KnowledgeBase, five of the most popular licenses are:

• MIT License
• GNU General Public License (GPL) 2.0—this is more restrictive and requires that copies of modified code are made available for public use
• Apache License 2.0
• GNU General Public License (GPL) 3.0
• BSD License 2.0 (3-clause, New or Revised)—this is less restrictiveiv

When source code is changed, OSS must include what was altered as well as the methods involved. Depending on the license terms, the software resulting from these modifications may or may not be required to be made available for free.iii

[More to come ...]