This is a special build of Apache Solr Based on the following patches...

http://wiki.apache.org/solr/FieldCollapsing
http://blog.jteam.nl/2009/10/20/result-grouping-field-collapsing-with-solr/
https://issues.apache.org/jira/browse/SOLR-236

The last patch applied to this release was created on:
https://issues.apache.org/jira/secure/attachment/12425775/field-collapse-5.patch

Text File  Licensed for inclusion in ASF works      
field-collapse-5.patch      
2009-11-22 10:00 PM     
Martijn van Groningen   
244 kB

Project has been created under an alternate groupId to 
be supported within the DSpace communit and distributed 
within the the org.dspace groupId.