Kronolith is the Horde calendar application. It provides web-based calendars backed by a SQL database or a Kolab server. Supported features include Ajax and mobile interfaces, shared calendars, remote calendars, invitation management (iCalendar/iTip), free/busy management, resource management, alarms, recurring events, and a sophisticated day/week view which handles arbitrary numbers of overlapping events.

This package is part of Horde, a web application Framework written in PHP with modules like IMP (webmail), Turba (contacts), Kronolith (calendar), Nag (task list), Gollem (file manager), etc.