Browserify [1] is huge and is built on the stream principle. Streams do a bit of processing and can be combined. As far as q, I have seen it used in a couple places but don't have anything big-ticket off the top of my head. Here's the official public list: https://npmjs.org/browse/depended/q

[1] http://browserify.org/

I've f.e. used https://github.com/lloyd/node-compute-cluster which basically is a broker between various computation processes in node.