Apache Solr and Drupal 7
In a nutshell, Solr is an open source enterprise search platform from the Apache Lucene project. Its major features include powerful full-text search, hit highlighting, faceted search, dynamic clustering, database integration, and rich document (e.g., Word, PDF) handling.
Solr uses the Lucene Java search library at its core for full-text indexing and search, and has REST-like HTTP/XML and JSON APIs that make it easy to use from virtually any programming language.
From what I've heard so far, Solr can also be well integrated with Drupal 7. I will definitely post an update as soon as I know more. Sounds very exciting
November 29th, 2011