Do we know what's behind this on the server? Is this a Node.js thing? (perhaps obvious to many, but I'm not down with the server-side js scripting and templatin

Do we know what's behind this on the server? Is this a Node.js thing? (perhaps obvious to many, but I'm not down with the server-side js scripting and templating lingo.) Creating a site from a json file sounds good. I defintely want to play with that, but what is required on server?