I understand that open source products can be sold for a profit as long as the code is released. So how do Commercial Modules for FreePBX work? Are they written in a proprietary sense or are they, too, open source? I don’t know enough about the GPL to know where having to release source code begins and ends. How do the Commercial Modules work with the GPL compared to the core program and open source modules?
Since Sangoma is the copyright holder of FreePBX we and only we can release non GPL add on for FreePBX. Anyone else has to release any add on that interact inside FreePBX GUI or modifications to FreePBX as GPL.
Okay, so it’s a copyright/owner issue. Because Sangoma owns FreePBX (even though the core product is open source) you can release additions that are closed source and don’t have to provide the code. But if an individual outside of Sangoma wrote an addition, they could be free to ask money for it but would have the make the code public. Is that correct?
Essentially, yes this is correct. But the onus is not just to make the code public, the code must be released under license compatible with the FreePBX GPL license.
Can this mean that if Sangoma wanted to, they could make the whole FreePBX closed source and only release enough of the Asterisk pieces to comply with Asterisk’s license?
AFAIK, once a line of code is released as GPLx, then it can’t retroactively be changed to a more restrictive license.
@lgaetz, I wasn’t clear in my comment about making FreePBX private.
If, at the beginning, FreePBX was closed source, they wouldn’t have had to release any code, correct? But how would the open source Asterisk pieces of the software work with the closed source pieces? Would some code have to be released while other parts could maintain private?
As long as you are arm’s length from the GPL you don’t need your code to be GPL.
Side note: Nothing in any of these responses should be taken as “Legal Advice” We are not lawyers.
Licensing is at it’s base one thing.
I own this widget.
You want to use this widget.
I grant you to use this widget under these terms.
A license is simply consent. Without consent to do a thing, you can’t do it.
No matter what the widget or terms that is licensing in a nut shell.
License compatibility: https://en.wikipedia.org/wiki/License_compatibility
Choosing a license: https://choosealicense.com/
Always consult a licensed legal professional in your state for appropriate legal advice.
This is more out of curiosity. I’m not developing anything myself.
It was more how/why many of the modules are open and how/why the commercial modules are closed.
That link about choosing a license is helpful. Thanks @jfinstrom.
In the end the only person who can bring a claim for GPL license violation is the License Holder which is Sangoma Technologies. It’s why we are allowed to do commercial modules as we are the only ones that could sue over a GPL violation. Same is true with Digium as it relates to Asterisk and why for 15 years when G729 codec was not GPL but a licensed module the only legal place you could buy the license was from Digium as they are the only entity that can exempt themselves from the GPL requirement with non GPL add on. This is known by many as dual license.