apt-xapian-index 0.47ubuntu8 (amd64 binary) in ubuntu xenial

 This package provides update-apt-xapian-index, a tool to maintain a Xapian
 index of Debian package information in /var/lib/apt-xapian-index, and
 axi-cache, a command line search tool that uses the index.
 .
 axi-cache allows one to search packages very quickly, and it also interfaces
 with the shell command line completion in a smart way, providing
 context-sensitive keyword and tag suggestions even before the search command
 is actually run.
 .
 update-apt-xapian-index allows plugins to be installed in
 /usr/share/apt-xapian-index to index all sorts of extra information, such as
 Debtags tags, popcon information, package ratings and anything else that would
 fit.
 .
 The index generated by update-apt-xapian-index is self-documenting, as it
 contains an autogenerated README file with information on the index layout and
 all the data that can be found in it.