I've been a fan of Signal since it was RedPhone and TextSecure and my professional relationship with Moxie is quite recent in the scheme of watching the rise of his projects. I apologize if my lack of awareness was offensive, it was unintended.

Edit: Just to be clear, I don't think you need to have the server open-sourced to trust the end to end encryption of the messages, but that's just one part of the overall trust model.