There are almost too many to track but, every now and then, one comes up that blows me away. I have recently had a lot of success with lucene/solr and wish I h

There are almost too many to track but, every now and then, one comes up that blows me away. I have recently had a lot of success with lucene/solr and wish I had used it for years! Which have you found useful and want to help bring attention to? Even if relatively large but you want to emphasize, give a shout!