PUBLIC MARKS with tags jabber & ejabberd

Pubsub nodes are organized in a hierarchical tree, similar to a file system. mod_pubsub imposes a special structure on this tree. There is a special node, pubsub/nodes, that contains all other created nodes. Nodes of users have names like home/server/username/whatever. If you try to create a node whose name doesn't fit that pattern, you will get an error. If you don't specify a name (i.e. create an instant node), the server generates a name that fits this pattern

Some says that it's the future of feeds, at least server-to-server subscriptions.