As its name implies, couchdb-lucene is based on the well known Lucene library. While I think that such a solution is providing a lot of features and flexibility, my concern is that it also brings additional complexity in terms of scalability as you’ll not only need to take care of scaling CouchDB, but also your Lucene indexes. On the other hand, indexer is using a much simpler approach and stores the indexes directly in the CouchDB, but it is still a prototype version.
But that’s just my opinion, so I’m wondering which one of these would you favor?
To learn more about these projects you can check the following resources:
And for more libraries and projects make sure you check the NoSQL Libraries.