OK, so this tells me that this is a commercial solution that gives you the flexibility of an open source PBX because many commercial PBXes do not do that. They don't let you install FOP2 or other third party programs. They don't let you write hooks into the PBX code, etc. For example, Switchvox vs PBXAct: which one gives you the same flexibility to do what you do with FreePBX? PBXAct, because Switchvox doesn't let you do such a thing.
My critic of that is, could be worded better. However, I in no way take that as "PBXAct is open source".