libxapian30 binary package in Ubuntu Bionic amd64

 This package contains the core Xapian runtime library.
 .
 The Xapian search engine library is a highly adaptable toolkit which allows
 developers to easily add advanced indexing and search facilities to their own
 applications. It implements the probabilistic model of information retrieval,
 and provides facilities for performing ranked free-text searches, relevance
 feedback, phrase searching, boolean searching, stemming, and simultaneous
 update and searching. It is highly scalable, and is capable of working with
 collections containing hundreds of millions of documents.

Source package