Apache Lucene is a high-performance, full-featured text search engine library written entirely in Java. It is a technology suitable for nearly any application that requires full-text search, especially cross-platform.

This release contains numerous bug fixes, optimizations, and improvements, some of which are highlighted below. The release is available for immediate download at: http://lucene.apache.org/core/mirrors-core-latest-redir.html

Lucene 4.4 Release Highlights:

* New Replicator module: replicate index revisions between server and client. See http://shaierera.blogspot.com/2013/05/the-replicator.html

* New AnalyzingInfixSuggester: finds suggestions based on matches to any tokens in the suggestion, not just based on pure prefix matching.  See http://blog.mikemccandless.com/2013/06/a-new-lucene-suggester-based-on-infix.html

* New PatternCaptureGroupTokenFilter: emit multiple tokens, one for each capture group in one or more Java regexes.

* New Lucene Facet module features:
  * Added dynamic (no taxonomy index used) numeric range faceting (see http://blog.mikemccandless.com/2013/05/dynamic-faceting-with-lucene.html)
  * Arbitrary Querys are now allowed for per-dimension drill-down on DrillDownQuery and DrillSideways, to support future dynamic faceting.
  * New FacetResult.mergeHierarchies: merge multiple FacetResult of the same dimension into a single one with the reconstructed hierarchy.

* FST’s Builder can now handle more than 2.1 billion “tail nodes” while building a minimal FST.

* FieldCache Ints and Longs now use bit-packing to save memory. String fields have more efficient compression if there are many unique terms.

* Improved compression for NumericDocValues for dates and fields with very small numbers of unique values.

* New IndexWriter.hasUncommittedChanges(): returns true if there are changes that have not been committed.

* multiValuedSeparator in PostingsHighlighter is now configurable, for cases where you want a different logical separator between field values.

* NorwegianLightStemFilter and NorwegianMinimalStemFilter have been extended to handle “nynorsk”.

* New ScandinavianFoldingFilter and ScandinavianNormalizationFilter.

* Easier compressed norms: Lucene42NormsFormat now takes an overhead parameter, allowing for values other than PackedInts.FASTEST.

* Analyzer now has an additional tokenStream(String fieldName, String text) method, so wrapping by StringReader for common use is no longer needed.

* New SimpleMergedSegmentWarmer: just ensures that data structures (terms, norms, docvalues, etc.) are initialized.

* IndexWriter flushes segments to the compound file format by default.

* Various bugfixes and optimizations since the 4.3.1 release.