Wagn is an interesting wiki implementation. It's a "real" wiki, requiring a server, not one of the personal or desktop wiki implementations that I prefer.
"In Wagn, everything is a card." And I like that, even if I don't quite see why this makes Wagn special.
It's written in Ruby, which needs to be installed for it to work.
It's quite a bit over-hyped: "We really hope Wagn will continue to do good in the world by making it easier for people to collaborate on, organize, and trumpet their ideas in profound and meaningful ways."
To be sure, we need more people, who "trumpet their ideas in profound and meaningful ways."
Or do we? I'd actually be more interested in more profound and meaningful ideas, not in more profound and meaningful trumpeting, which seems to me a contradictio in adiecto.
There are two ways to install and maintain it. Either you do it yourself or you pay them a consulting fee.