SolrHQ is an expandable hosted Apache Solr solution, making setting up Solr Search easy for everybody even slightly technical. It can be used by programmers using provided sample code, or by any CMS site owner using the WordPress plugin or Joomla extension.
Each SolrHQ instance is an extended install of the current Solr release. Extensions allow for client level remote administration and system level management of the overall system.
Lucene is open source search engine project of the Apache Software Foundation.
Per ASF: “Apache Lucene is a high-performance, full-featured text search engine software library written entirely in Java.”
Solr is a subproject of the Lucene project that created a fully featured search engine.
per ASF: “Apache Solr is a software product that provides an enterprise search server and services based on Apache Lucene.”
Lucene and Solr are trademarks of the Apache Software Foundation.