Succinctly, Amber runs on your web server, analyzes your published content, and archives the things you link to. If a browser follows a link and it isn’t available, AMBER will intervene and dish up a mirrored version from the local store on your web server.
It isn’t SaaS. It isn’t a global peer-to-peer network of connected cloud thingamajigs. It’s a piece of software that runs on your server and it doesn’t need to check in with anyone.
AMBER — from The Berkman Center for Internet & Society