We are getting closer and closer to the final release of Apache Lucene and Solr 4.0! Just a few minutes ago, the 4.0 beta of Apache Lucene library and Solr search servers were released.
A full list of changes in Apache Lucene 4.0 beta, compared to the 4.0 alpha version, can be found at the following address: http://wiki.apache.org/lucene-java/ReleaseNote40beta. The full list of changes in Apache Solr 4.0 can be found at the Solr wiki as well: http://wiki.apache.org/solr/ReleaseNote40beta.
In order to download the Apache Lucene 4.0 beta library, please go to: http://www.apache.org/dyn/closer.cgi/lucene/java/. Apache Solr 4.0 beta can be downloaded at the following address: http://www.apache.org/dyn/closer.cgi/lucene/solr/.
Please note that not all mirrors have to be updated yet.