Hounder - Technically, this could also be grouped with Lucene. Hounder is a complete out of the box search engine by Flaptor. It's written in Java and includes a distributed focused crawler (that includes a classifier), indexing, and search system. It's most similar to Solr and Nutch, see their comparison. It appears to use Lucene as it's underlying search library. Hounder powers Wordpress.com's search capability. Flaptor also claims they have a 300 million document collection running on approximately 30 nodes. They released their cluster management system as Clusterfest.Don't miss Flaptor's blog.
Monday, May 19
Hounder: A new open source search engine
I update my list of open source search libraries and added Hounder. From my description: