LDP is an application distribution platform where each node has it own nodejs (running apps) and it own couchdb instance. The apps are stored into the DB and they are replicated as the rest of the data through the replication system of couchdb. The apps use also couchdb as the persistent storage system. For horizontal scaling you have to add a node, thats all. The new node replicates against other node, it retrieves the data and the apps and nodejs automatically runs each application.  When a application code is updated, the change is replicated automatically by couchdb (as the rest of information) and notifies the change to nodejs. It restarts that application with the new version. So if you update the application code in a node of the net automatically all the instances of the application are updated.  The intend of this development is to have the posibility of deploying small applications based on nodejs easyly in a very dinamic way with just adding a node.  This software is under heavy development and it is in a conceptual and testing phase, it's just an experiment right now.