Ferret (a.k.a Ruby Lucene)
Interesting interview with the creator of Ferret at http://on-ruby.blogspot.com/2006/10/ruby-hacker-interview-dave-balmain.html
Talks about some of the performance changes he has made in Ferret C version to make it run a lot faster than Java Lucene. He says he doubts they can be ported to Java, but I wonder if the Java version might still benefit.

Note: the benefits of this are mostly in indexing…