Apache Lucene 3.1.0 and Apache Solr 3.1.0 →
This is the first release bringing Lucene and Solr release versions in sync. There are numerous bug fixes, optimizations and new features. Download from here
Nice features:
On 64bit Windows and Solaris JVMs, MMapDirectory is now the default implementation (returned by FSDirectory.open). MMapDirectory also enables unmapping if the JVM supports it.
JSON document indexing
Apache UIMA integration for metadata extraction
Don’t know yet if field collapsing is included in this one though
