Zebra is
a high-performance, general-purpose structured text indexing
and retrieval engine.
It reads structured records in a variety
of input formats (eg. email, XML, MARC) and allows access
to them through exact boolean search expressions and relevance-ranked
free-text queries.
Zebra supports large databases (more than ten gigabytes
of data, tens of millions of records). It supports incremental,
safe database updates on live systems. You can access data
stored in Zebra using a variety of Index Data tools (eg.
YAZ and PHP/YAZ) as well as commercial and freeware Z39.50
clients and toolkits.
Zebra is free software, available under the GPL license.
It may be used by anyone without charge. If you wish to
incorporate Zebra into a commercial software distribution,
please contact us about alternative licenses.