< / >

NowJS is a cool abstraction layer that tries to emulate a shared stack between the server (NodeJS) and clients (browsers). You end up with something like this on the server:

var everyone = require("now").initialize(httpServer);
everyone.now.getServerInfo = function(callback) {
  db.doQuery(callback);
}

Which allows you to do this on the client:

<script type="text/javascript">
  now.getServerInfo(function(data) {
    // data contains the query results
  });
</script>

It uses Socket.IO under the hood to keep the data in sync, so it should use WebSockets when available, and fallback to alternatives when needed.