​https://en.wikipedia.org/wiki/Information_retrieval

Lucene

• ​https://en.wikipedia.org/wiki/Lucene
• ​python-lucene

CLucene (2011 and more recent versions on Debian)

• ​http://clucene.sourceforge.net/
• ​clucene-core
• Used by LibreOffice and Dovecot (IMAP server) on Debian
• ​https://pecl.php.net/package/clucene

Lucene++ (uses libboost)

• ​https://github.com/luceneplusplus/LucenePlusPlus
• ​liblucene++

Qt Lucene (Used by Qt help)

• ​libqt5clucene5
• ​https://mail.python.org/pipermail/python-announce-list/2011-December/009287.html (Python, Lucene and Qt Help)

Lucy

• ​Apache solr vs Apache Lucy
• ​http://lucy.apache.org/faq.html
• ​liblucy-perl

Plucene (Perl port)

• ​libplucene-perl

Ferret (ancestor of Lucy)

• ​ruby-ferret

Xapian

• ​xapian-bindings, ​xapian-core

Norch (Javascript)

• ​https://github.com/fergiemcdowall/norch