I've started to think that a merge of Solr and Lucene would be in the best interest of both projects.
Recently, Solr as pulled back from using Lucene trunk (or even the latest version), as the increased amount of change between releases (and in-between releases) made it impractical to deal with. This is a pretty big negative for Lucene, since Solr is the biggest Lucene user (where people are directly exposed to lucene for the express purpose of developing search features). I know Solr development has always benefited hugely from users using trunk, and Lucene trunk has now lost all the solr users. Some in Lucene development have expressed a desire to make Lucene more of a complete solution, rather than just a core full-text search library... things like a data schema, faceting, etc. The Lucene project already has an enterprise search platform with these features... that's Solr. Trying to pull popular pieces out of Solr makes life harder for Solr developers, brings our projects into conflict, and is often unsuccessful (witness the largely failed migration of FunctionQueries from Solr to Lucene). For Lucene to achieve the ultimate in usability for users, it can't require Java experience... it needs higher level abstractions provided by Solr. The other benefit to Lucene would be to bring features to developers much sooner... Solr has had features years before they were developed in Lucene, and currently has more developers working with it. Esp with Solr not using Lucene trunk, if a Solr developer wants a feature quickly, they cannot add it to Lucene (even if it might make sense there) since that introduces a big unpredictable lag - when that version of Lucene make it's way into Solr. The current divide is a bit unnatural. For maximum benefit of both projects, it seems like Solr and Lucene should essentially merge. Lucene core would essentially remain as it is, but: 1) Solr would go back to using Lucene's trunk 2) For new Solr features, there would be an effort to abstract it such that non-Solr users could use the functionality (faceting, field collapsing, etc) 3) For new Lucene features, there would be an effort to integrate it into Solr. 4) Releases would be synchronized... Lucene and Solr would release at the same time. -Yonik
