What Are the Next Big Things In Open Source?

Last week, SDTimes compiled a list of the five next big things in open source. I'd like to hear what you think are the open source technologies to watch in 2011.The SDTimes list includes technologies such as HBase and CouchDB, building on the NoSQL momentum. An interesting observation is that the addition of Eclipse Virgo to the already rich  Eclipse eco-system really adds weight to the runtime