akonadi-backend-sqlite 4:15.12.3-0ubuntu4 (amd64 binary) in ubuntu xenial

 Akonadi is an extensible cross-desktop Personal Information Management (PIM)
 storage service. It provides a common framework for applications to store and
 access mail, calendars, addressbooks, and other PIM data.
 .
 This package installs everything what's needed for Akonadi to work with SQLite
 as underlying data storage engine. Since SQLite is an embedded database
 engine, a separate SQL server daemon is not necessary.
 .
 In addition, the package contains an improved QSql driver for SQLite named
 "QSQLite3". It can be used by any application that needs to access SQLite
 databases via standard Qt QSql framework.