Apache Thrift
Apache Avro
MessagePack
ProtocolBuffers

http://www.zerorpc.io/ for python and node.js

storm switching from zeromq to netty
http://storm.apache.org/2013/12/08/storm090-released.html
http://yahooeng.tumblr.com/post/64758709722/making-storm-fly-with-netty

storm.yaml
    storm.messaging.transport: "backtype.storm.messaging.netty.Context"
    storm.messaging.netty.server_worker_threads: 1
    storm.messaging.netty.client_worker_threads: 1
    storm.messaging.netty.buffer_size: 5242880
    storm.messaging.netty.max_retries: 100
    storm.messaging.netty.max_wait_ms: 1000
    storm.messaging.netty.min_wait_ms: 100
    
http://netty.io/index.html

rpc with netty and messagepack:
https://msgpack.wordpress.com/2010/05/04/introduction-to-messagepack-rpc/