Elastic Search (via) Solr has competition! Like Solr, Elastic Search provides a RESTful JSON HTTP interface to Lucene. The focus here is on distribution, auto-sharding and high availability. It’s even easier to get started with than Solr, partly due to the focus on providing a schema-less document store, but it’s currently missing out on a bunch of useful Solr features (a web interface and faceting are the two that stand out). The high availability features look particularly interesting. UPDATE: I was incorrect, basic faceted queries are already supported.