How do Solr, Lucene, Sphinx and Searchify compare?
My answer to How do Solr, Lucene, Sphinx and Searchify compare? on Quora
Lucene is a Java library for creating and searching through a full text index. If you want to make use of it, you’ll need to write your own Java code that integrates with it.
Solr is a web service that is built on top of the Lucene library. You can talk to it over HTTP from any programming language—so you can take advantage of the power of Lucene without having to write any Java code at all. Solr also adds a number of features that Lucene leaves out such as sharding and replication.