In the realm of computer software, “Open Source” refers to software whose human-readable code is available to the individuals and organizations who run the code. All though there is much debate over what constitutes “Free Software” vs “Open Source Software,” the Free Software Foundation’s “List of Freedoms” provides an easy litmus test for whether software is free.
These freedoms are to:
- run the code,
- see & change the code,
- redistribute the code,
- and redistribute modifications to the code.
Of note is the fact that nothing about the definition of “Free Software” mandates that the software be available at zero cost, so as a result, we prefer the term “open” to “free” to avoid confusion.
For further reading on the topic of open source, take a look at the Open Source Initiative’s Open Source Definition (By Bruce Perens), and the Free Software Foundation’s “What is free software?” Links to these documents as well as other relevant information is available in the “Suggested Reading” section: