I'm a bit late to the party but I wanted to mention that in addition to being a tool created to support the kind of collaborative decision-making that happens in cooperative models (which they are using it for at CoLab, as solarlion kindly mentioned already) Loomio [0] is itself structured as a cooperative with 12 worker-members and growing.
Loomio is part of the larger Enspiral ecosystem (as te_chris already mentioned), which is a network of startups doing business differently, with a social good focus and also upending internal organisation. We're innovating new ways to do core business processes in collaborative, distributed ways. Loomio is an example of that for decision-making, and we're also doing the same in budgeting, strategy setting, governance, and more.
We're quite passionate about the cooperative model and collaborative process design and are happy to talk more in-depth with anyone who is interested.