It’s official, Apache Lucene 3.1.0 and Apache Solr 3.1.0 are officially released.  Keep an eye here for more on the new features and functionality.

Here’s the release announcements as just sent to the mailing lists:

March 2011, Apache Lucene 3.1 available
The Lucene PMC is pleased to announce the release of Apache Lucene 3.1.

This release contains numerous bug fixes, optimizations, and
improvements, some of which are highlighted below.  The release
is available for immediate download at http://www.apache.org/dyn/closer.cgi/lucene/java.
See the CHANGES.txt
file included with the release for a full list of details.

Lucene 3.1 Release Highlights

* Numerous performance improvements: faster exact PhraseQuery; merging
 favors segments with deletions; primary key lookup is faster;
 IndexWriter.addIndexes(Directory[]) uses file copy instead of
 merging; various Directory performance improvements; compound file
 is dynamically turned off for large segments; fully deleted segments
 are dropped on commit; faster snowball analyzers (in contrib);
 ConcurrentMergeScheduler is more careful about setting priority of
 merge threads.

* ReusableAnalyzerBase makes it easier to reuse TokenStreams
 correctly.

* Improved Analysis capabilities: Improved Unicode support, including
 Unicode 4, more friendly term handling (CharTermAttribute), easier
 object reuse and better support for protected words in lossy token
 filters (e.g. stemmers).

* ConstantScoreQuery now allows directly wrapping a Query.

* IndexWriter is now configured with a new separate builder API,
 IndexWriterConfig.  You can now control IndexWriter's previously
 fixed internal thread limit by calling setMaxThreadStates.

* IndexWriter.getReader is replaced by IndexReader.open(IndexWriter).
 In addition you can now specify whether deletes should be resolved
 when you open an NRT reader.

* MultiSearcher is deprecated; ParallelMultiSearcher has been
 absorbed directly into IndexSearcher.

* 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.

* New TotalHitCountCollector just counts total number of hits.

* ReaderFinishedListener API enables external caches to evict entries
 once a segment is finished.

March 2011, Apache Solr 3.1 available

The Lucene PMC is pleased to announce the release of Apache Solr 3.1.

This release contains numerous bug fixes, optimizations, and
improvements, some of which are highlighted below.  The release is
available for immediate download at http://www.apache.org/dyn/closer.cgi/lucene/solr.
See the CHANGES.txt file included with the release for a full list of
details as well as instructions on upgrading.

What's in a Version? 

The version number for Solr 3.1 was chosen to reflect the merge of
development with Lucene, which is currently also on 3.1.  Going
forward, we expect the Solr version to be the same as the Lucene
version.  Solr 3.1 contains Lucene 3.1 and is the release after Solr 1.4.1.

Solr 3.1 Release Highlights

* Numeric range facets (similar to date faceting).

* New spatial search, including spatial filtering, boosting and sorting capabilities.

* Example Velocity driven search UI at http://localhost:8983/solr/browse

* A new termvector-based highlighter

* Extend dismax (edismax) query parser which addresses some
 missing features in the dismax query parser along with some
 extensions.

* Several more components now support distributed mode:
 TermsComponent, SpellCheckComponent.

* A new Auto Suggest component.

* Ability to sort by functions.

* JSON document indexing

* CSV response format

* Apache UIMA integration for metadata extraction

* Leverages Lucene 3.1 and it's inherent optimizations and bug fixes
 as well as new analysis capabilities.

* Numerous improvements, bug fixes, and optimizations.