Open source is an industry term, the code is NOT open, it's available. I can read it. I cannot use it in anything that might net some profit in the future. "open-source" is defined by the OSI here: https://opensource.org/osd/.
To be fair to OP, they didn't say open source until their response to your comment. They just said source code released for non-profit use. You are correct, though, that this is not open source.
Looks like it is an overlay for volume.